Vascular Disorders

Section 16.1: Atherosclerosis

This section includes text excerpted from “Atherosclerosis,” National Heart, Lung, and Blood Institute (NHLBI), June 22, 2016.

What Is Atherosclerosis?

Atherosclerosis is a disease in which plaque builds up inside your arteries. Arteries are blood vessels that carry oxygen-rich blood to your heart and other parts of your body. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows your arteries. This limits the flow of oxygen-rich blood to your organs and other parts of your body. Atherosclerosis can lead to serious problems, including heart attack, stroke, or even death.

Atherosclerosis-Related Diseases

Atherosclerosis can affect any artery in the body, including arteries in the heart, brain, arms, legs, pelvis, and kidneys. As a result, different diseases may develop based on which arteries are affected.

Coronary Heart Disease (CHD)

CHD, also called coronary artery disease, occurs when plaque builds up in the coronary arteries. These arteries supply oxygen-rich blood to your heart. Plaque narrows the coronary arteries and reduces blood flow to your heart muscle. Plaque buildup also makes it more likely that blood clots will form in your arteries. Blood clots can partially or completely block blood flow. If blood flow to your heart muscle is reduced or blocked, you may have angina (chest pain or discomfort) or a heart attack. Plaque also can form in the heart's smallest arteries. This disease is called coronary microvascular disease (MVD). In coronary MVD, plaque doesn't cause blockages in the arteries as it does in CHD.

 


Figure 16.1. Atherosclerosis





Figure 16.1. Atherosclerosis. Figure A shows a normal artery with normal blood flow. The inset image shows a cross-section of a normal artery. Figure B shows an artery with plaque buildup. The inset image shows a cross-section of an artery with plaque buildup.

Carotid Artery Disease

Carotid artery disease occurs if plaque builds up in the arteries on each side of your neck (the carotid arteries). These arteries supply oxygen-rich blood to your brain. If blood flow to your brain is reduced or blocked, you may have a stroke.

Peripheral Artery Disease

Peripheral artery disease (P.A.D.) occurs if plaque builds up in the major arteries that supply oxygen-rich blood to your legs, arms, and pelvis. If blood flow to these parts of your body is reduced or blocked, you may have numbness, pain, and sometimes, dangerous infections.

Chronic Kidney Disease

What Causes Atherosclerosis?

The exact cause of atherosclerosis isn't known. However, studies show that atherosclerosis is a slow, complex disease that may start in childhood. It develops faster as you age. Atherosclerosis may start when certain factors damage the inner layers of the arteries. These factors include:

Plaque may begin to build up where the arteries are damaged. Over time, plaque hardens and narrows the arteries. Eventually, an area of plaque can rupture (break open). When this happens, blood cell fragments called platelets stick to the site of the injury. They may clump together to form blood clots. Clots narrow the arteries even more, limiting the flow of oxygen-rich blood to your body. Depending on which arteries are affected, blood clots can worsen angina (chest pain) or cause a heart attack or stroke. Researchers continue to look for the causes of atherosclerosis. They hope to find answers to questions such as:

Who Is at Risk for Atherosclerosis?

The exact cause of atherosclerosis isn't known. However, certain traits, conditions, or habits may raise your risk for the disease. These conditions are known as risk factors. The more risk factors you have, the more likely it is that you'll develop atherosclerosis. You can control most risk factors and help prevent or delay atherosclerosis. Other risk factors can't be controlled.

Major Risk Factors

Although age and a family history of early heart disease are risk factors, it doesn't mean that you'll develop atherosclerosis if you have one or both. Controlling other risk factors often can lessen genetic influences and prevent atherosclerosis, even in older adults. Studies show that an increasing number of children and youth are at risk for atherosclerosis. This is due to a number of causes, including rising childhood obesity rates.

What Are the Signs and Symptoms of Atherosclerosis?

Atherosclerosis usually doesn't cause signs and symptoms until it severely narrows or totally blocks an artery. Many people don't know they have the disease until they have a medical emergency, such as a heart attack or stroke. Some people may have signs and symptoms of the disease. Signs and symptoms will depend on which arteries are affected.

Coronary Arteries

The coronary arteries supply oxygen-rich blood to your heart. If plaque narrows or blocks these arteries (a disease called coronary heart disease, or CHD), a common symptom is angina. Angina is chest pain or discomfort that occurs when your heart muscle doesn't get enough oxygen-rich blood. Angina may feel like pressure or squeezing in your chest. You also may feel it in your shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion. The pain tends to get worse with activity and go away with rest. Emotional stress also can trigger the pain.

Other symptoms of CHD are shortness of breath and arrhythmias. Arrhythmias are problems with the rate or rhythm of the heartbeat. Plaque also can form in the heart's smallest arteries. This disease is called coronary microvascular disease (MVD). Symptoms of coronary MVD include angina, shortness of breath, sleep problems, fatigue (tiredness), and lack of energy.

Carotid Arteries How Is Atherosclerosis Diagnosed?

Your doctor will diagnose atherosclerosis based on your medical and family histories, a physical exam, and test results.

Physical Exam

During the physical exam, your doctor may listen to your arteries for an abnormal whooshing sound called a bruit. Your doctor can hear a bruit when placing a stethoscope over an affected artery. A bruit may indicate poor blood flow due to plaque buildup. Your doctor also may check to see whether any of your pulses (for example, in the leg or foot) are weak or absent. A weak or absent pulse can be a sign of a blocked artery.

Diagnostic Tests

Your doctor may recommend one or more tests to diagnose atherosclerosis. These tests also can help your doctor learn the extent of your disease and plan the best treatment.

Blood Tests

Blood tests check the levels of certain fats, cholesterol, sugar, and proteins in your blood. Abnormal levels may be a sign that you're at risk for atherosclerosis.

Electrocardiogram (EKG)

An EKG is a simple, painless test that detects and records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through the heart. An EKG can show signs of heart damage caused by CHD. The test also can show signs of a previous or current heart attack.

Chest X-Ray

A chest X-ray takes pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. A chest X-ray can reveal signs of heart failure.

Ankle/Brachial Index

This test compares the blood pressure in your ankle with the blood pressure in your arm to see how well your blood is flowing. This test can help diagnose P.A.D.

Echocardiography

Echocardiography (echo) uses sound waves to create a moving picture of your heart. The test provides information about the size and shape of your heart and how well your heart chambers and valves are working. Echo also can identify areas of poor blood flow to the heart, areas of heart muscle that aren't contracting normally, and previous injury to the heart muscle caused by poor blood flow.

Computed Tomography (CT) Scan

A CT scan creates computer-generated pictures of the heart, brain, or other areas of the body. The test can show hardening and narrowing of large arteries. A cardiac CT scan also can show whether calcium has built up in the walls of the coronary (heart) arteries. This may be an early sign of CHD.

Stress Testing

As part of some stress tests, pictures are taken of your heart while you exercise and while you rest. These imaging stress tests can show how well blood is flowing in various parts of your heart. They also can show how well your heart pumps blood when it beats.

Angiography

Angiography is a test that uses dye and special X-rays to show the inside of your arteries. This test can show whether plaque is blocking your arteries and how severe the blockage is. A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. Dye that can be seen on an X-ray picture is injected through the catheter into the arteries. By looking at the X-ray picture, your doctor can see the flow of blood through your arteries.

Other Tests

Other tests are being studied to see whether they can give a better view of plaque buildup in the arteries. Examples of these tests include MRI and positron emission tomography (PET).

How Is Atherosclerosis Treated?

Treatments for atherosclerosis may include heart-healthy lifestyle changes, medicines, and medical procedures or surgery. The goals of treatment include:

Heart-Healthy Lifestyle Changes

Your doctor may recommend heart-healthy lifestyle changes if you have atherosclerosis. Heart-healthy lifestyle changes include heart-healthy eating, aiming for a healthy weight, managing stress, physical activity, and quitting smoking.

Medicines

Sometimes lifestyle changes alone aren't enough to control your cholesterol levels. For example, you also may need statin medications to control or lower your cholesterol. By lowering your blood cholesterol level, you can decrease your chance of having a heart attack or stroke. Doctors usually prescribe statins for people who have:

Doctors may discuss beginning statin treatment with people who have an elevated risk for developing heart disease or having a stroke. Your doctor also may prescribe other medications to:

Take all medicines regularly, as your doctor prescribes. Don't change the amount of your medicine or skip a dose unless your doctor tells you to. You should still follow a heart healthy lifestyle, even if you take medicines to treat your atherosclerosis.

Medical Procedures and Surgery

If you have severe atherosclerosis, your doctor may recommend a medical procedure or surgery.

How Can Atherosclerosis Be Prevented or Delayed?

Taking action to control your risk factors can help prevent or delay atherosclerosis and its related diseases. Your risk for atherosclerosis increases with the number of risk factors you have. One step you can take is to adopt a healthy lifestyle, which can include:

Other steps that can prevent or delay atherosclerosis include knowing your family history of atherosclerosis. If you or someone in your family has an atherosclerosis-related disease, be sure to tell your doctor. If lifestyle changes aren't enough, your doctor may prescribe medicines to control your atherosclerosis risk factors. Take all of your medicines as your doctor advises.

Section 16.2: Heart Attack

This section includes text excerpted from “Heart Attack,” National Heart, Lung, and Blood Institute (NHLBI), January 27, 2015.

What Is a Heart Attack?

A heart attack happens when the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart can't get oxygen. If blood flow isn't restored quickly, the section of heart muscle begins to die.

Heart attacks most often occur as a result of coronary heart disease (CHD), also called coronary artery disease. CHD is a condition in which a waxy substance called plaque builds up inside the coronary arteries. These arteries supply oxygen-rich blood to your heart.

 


Figure 16.2. Heart with Muscle Damage and a Blocked Artery





Figure 16.2. Heart with Muscle Damage and a Blocked Artery. Figure A is an overview of a heart and coronary artery showing damage (dead heart muscle) caused by a heart attack. Figure B is a cross-section of the coronary artery with plaque buildup and a blood clot.

A less common cause of heart attack is a severe spasm (tightening) of a coronary artery. The spasm cuts off blood flow through the artery. Spasms can occur in coronary arteries that aren't affected by atherosclerosis. Heart attacks can be associated with or lead to severe health problems, such as heart failure and life-threatening arrhythmias. Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Arrhythmias are irregular heartbeats. Ventricular fibrillation is a life-threatening arrhythmia that can cause death if not treated right away.

Who Is at Risk for a Heart Attack?

Certain risk factors make it more likely that you'll develop CHD and have a heart attack. You can control many of these risk factors.

Risk Factors You Can't Control

Risk factors that you can't control include:

Risk Factors You Can Control

The major risk factors for a heart attack that you can control include:

Some of these risk factors—such as obesity, high blood pressure, and high blood sugar—tend to occur together. When they do, it's called metabolic syndrome.

In general, a person who has metabolic syndrome is twice as likely to develop heart disease and five times as likely to develop diabetes as someone who doesn't have metabolic syndrome.

What Are the Symptoms of a Heart Attack?

Not all heart attacks begin with the sudden, crushing chest pain that often is shown on TV or in the movies. In one study, for example, one-third of the patients who had heart attacks had no chest pain. These patients were more likely to be older, female, or diabetic.

The symptoms of a heart attack can vary from person to person. Some people can have few symptoms and are surprised to learn they've had a heart attack. If you've already had a heart attack, your symptoms may not be the same for another one. It is important for you to know the most common symptoms of a heart attack and also remember these facts:

Some people don't have symptoms at all. Heart attacks that occur without any symptoms or with very mild symptoms are called silent heart attacks.

How Is a Heart Attack Diagnosed?

Your doctor will diagnose a heart attack based on your signs and symptoms, your medical and family histories, and test results.

Diagnostic Tests

EKG (Electrocardiogram)

An EKG is a simple, painless test that detects and records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through each part of the heart. An EKG can show signs of heart damage due to CHD and signs of a previous or current heart attack.

Blood Tests

During a heart attack, heart muscle cells die and release proteins into the bloodstream. Blood tests can measure the amount of these proteins in the bloodstream. Higher than normal levels of these proteins suggest a heart attack. Commonly used blood tests include troponin tests, CK or CK–MB tests, and serum myoglobin tests. Blood tests often are repeated to check for changes over time.

Coronary Angiography

Coronary angiography is a test that uses dye and special X-rays to show the insides of your coronary arteries. This test often is done during a heart attack to help find blockages in the coronary arteries. To get the dye into your coronary arteries, your doctor will use a procedure called cardiac catheterization.

A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. The tube is threaded into your coronary arteries, and the dye is released into your bloodstream. Special X-rays are taken while the dye is flowing through the coronary arteries. The dye lets your doctor study the flow of blood through the heart and blood vessels.

How Is a Heart Attack Treated?

Immediate Treatment

Certain treatments usually are started right away if a heart attack is suspected, even before the diagnosis is confirmed. These include:

Once the diagnosis of a heart attack is confirmed or strongly suspected, doctors start treatments promptly to try to restore blood flow through the blood vessels supplying the heart. The two main treatments are clot-busting medicines and percutaneous coronary intervention, also known as coronary angioplasty, a procedure used to open blocked coronary arteries.

Clot-Busting Medicines

Thrombolytic medicines, also called clot busters, are used to dissolve blood clots that are blocking the coronary arteries. To work best, these medicines must be given within several hours of the start of heart attack symptoms. Ideally, the medicine should be given as soon as possible.

Percutaneous Coronary Intervention

Other Treatments for Heart Attack

Other treatments for heart attack include:

Medicines

Your doctor may prescribe one or more of the following medicines:

You also may be given medicines to relieve pain and anxiety, and treat arrhythmias. Take all medicines regularly, as your doctor prescribes. Don't change the amount of your medicine or skip a dose unless your doctor tells you to.

Medical Procedures

Heart-Healthy Lifestyle Changes

Treatment for a heart attack usually includes making heart-healthy lifestyle changes. Your doctor also may recommend:

Taking these steps can lower your chances of having another heart attack.

Cardiac Rehabilitation

Your doctor may recommend cardiac rehabilitation (cardiac rehab) to help you recover from a heart attack and to help prevent another heart attack. Nearly everyone who has had a heart attack can benefit from rehab. Cardiac rehab is a medically supervised program that may help improve the health and well-being of people who have heart problems. The cardiac rehab team may include doctors, nurses, exercise specialists, physical and occupational therapists, dietitians or nutritionists, and psychologists or other mental health specialists.

Rehab has two parts:

How Can a Heart Attack Be Prevented?

Lowering your risk factors for coronary heart disease can help you prevent a heart attack. Even if you already have coronary heart disease, you still can take steps to lower your risk for a heart attack. These steps involve making heart-healthy lifestyle changes and getting ongoing medical care for related conditions that make heart attack more likely. Talk to your doctor about whether you may benefit from aspirin primary prevention, or using aspirin to help prevent your first heart attack.

Ongoing Care

Treat Related Conditions

Treating conditions that make a heart attack more likely also can help lower your risk for a heart attack. These conditions may include:

Section 16.3: High Blood Pressure

This section includes text excerpted from “High Blood Pressure,” National Heart, Lung, and Blood Institute (NHLBI), September 10, 2015.

What Is High Blood Pressure?

High blood pressure is a common disease in which blood flows through blood vessels (arteries) at higher than normal pressures.

Measuring Blood Pressure

Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps blood. High blood pressure, sometimes called hypertension, happens when this force is too high. Healthcare workers check blood pressure readings the same way for children, teens, and adults. They use a gauge, stethoscope or electronic sensor, and a blood pressure cuff. With this equipment, they measure:

Healthcare workers write blood pressure numbers with the systolic number above the diastolic number. For example: 118/76 mmHg. People read “118 over 76” millimeters of mercury.

Normal Blood Pressure

Normal blood pressure for adults is defined as a systolic pressure below 120 mmHg and a diastolic pressure below 80 mmHg. It is normal for blood pressures to change when you sleep, wake up, or are excited or nervous. When you are active, it is normal for your blood pressure to increase. However, once the activity stops, your blood pressure returns to your normal baseline range.

Blood pressure normally rises with age and body size. New born babies often have very low blood pressure numbers that are considered normal for babies, while older teens have numbers similar to adults.

Abnormal Blood Pressure

Abnormal increases in blood pressure are defined as having blood pressures higher than 120/80 mmHg. The following table outlines and defines high blood pressure severity levels.

Stages of High Blood Pressure in Adults

The ranges in the table are blood pressure guides for adults who do not have any short-term serious illnesses. People with diabetes or chronic kidney disease should keep their blood pressure below 130/80 mmHg. Although blood pressure increases seen in prehypertension are less than those used to diagnose high blood pressure, prehypertension can progress to high blood pressure and should be taken seriously.

 


Table 16.1. High Blood Pressure Severity Levels





Table 16.1. High Blood Pressure Severity Levels

Over time, consistently high blood pressure weakens and damages your blood vessels, which can lead to complications.

Types of High Blood Pressure

There are two main types of high blood pressure: primary and secondary high blood pressure.

Primary High Blood Pressure: Primary, or essential, high blood pressure is the most common type of high blood pressure. This type of high blood pressure tends to develop over years as a person ages.

Secondary High Blood Pressure: Secondary high blood pressure is caused by another medical condition or use of certain medicines. This type usually resolves after the cause is treated or removed.

Causes of High Blood Pressure

Changes, either from genes or the environment, in the body's normal functions may cause high blood pressure, including changes to kidney fluid and salt balances, the renin-angiotensin-aldosterone system, sympathetic nervous system activity, and blood vessel structure and function.

Biology and High Blood Pressure

Researchers continue to study how various changes in normal body functions cause high blood pressure. The key functions affected in high blood pressure include:

Kidney Fluid and Salt Balances

The kidneys normally regulate the body's salt balance by retaining sodium and water and excreting potassium. Imbalances in this kidney function can expand blood volumes, which can cause high blood pressure.

Renin-Angiotensin-Aldosterone System

The renin-angiotensin-aldosterone system makes angiotensin and aldosterone hormones. Angiotensin narrows or constricts blood vessels, which can lead to an increase in blood pressure. Aldosterone controls how the kidneys balance fluid and salt levels. Increased aldosterone levels or activity may change this kidney function, leading to increased blood volumes and high blood pressure.

Sympathetic Nervous System Activity

The sympathetic nervous system has important functions in blood pressure regulation, including heart rate, blood pressure, and breathing rate. Researchers are investigating whether imbalances in this system cause high blood pressure.

Blood Vessel Structure and Function

Changes in the structure and function of small and large arteries may contribute to high blood pressure. The angiotensin pathway and the immune system may stiffen small and large arteries, which can affect blood pressure.

Genetic Causes of High Blood Pressure

Much of the understanding of the body systems involved in high blood pressure has come from genetic studies. High blood pressure often runs in families. Years of research have identified many genes and other mutations associated with high blood pressure, some in the renal salt regulatory and renin-angiotensin-aldosterone pathways. However, these known genetic factors only account for 2 to 3 percent of all cases. Emerging research suggests that certain deoxyribonucleic acid (DNA) changes during fetal development also may cause the development of high blood pressure later in life.

Environmental Causes of High Blood Pressure

Environmental causes of high blood pressure include:

Unhealthy Lifestyle Habits

Unhealthy lifestyle habits can cause high blood pressure, including:

Overweight and Obesity

Research studies show that being overweight or obese can increase the resistance in the blood vessels, causing the heart to work harder and leading to high blood pressure.

Medicines

Prescription medicines such as asthma or hormone therapies, including birth control pills and estrogen, and over-the-counter medicines such as cold relief medicines may cause this form of high blood pressure. This happens because medicines can change the way your body controls fluid and salt balances, cause your blood vessels to constrict, or impact the renin-angiotensin-aldosterone system leading to high blood pressure.

Other Medical Causes of High Blood Pressure

Other medical causes of high blood pressure include other medical conditions such as chronic kidney disease, sleep apnea, thyroid problems, or certain tumors. This happens because these other conditions change the way your body controls fluids, sodium, and hormones in your blood, which leads to secondary high blood pressure.

Risk Factors for High Blood Pressure

Anyone can develop high blood pressure; however, age, race or ethnicity, being overweight, gender, lifestyle habits, and a family history of high blood pressure can increase your risk for developing high blood pressure.

Age

Blood pressure tends to rise with age. About 65 percent of Americans age 60 or older have high blood pressure. However, the risk for prehypertension and high blood pressure is increasing for children and teens, possibly due to the rise in the number of overweight children and teens.

Race/Ethnicity

High blood pressure is more common in African American adults than in Caucasian or Hispanic American adults. Compared with these ethnic groups, African Americans:

Overweight

You are more likely to develop prehypertension or high blood pressure if you're overweight or obese. The terms “overweight” and “obese” refer to body weight that's greater than what is considered healthy for a certain height.

Gender

Before age 55, men are more likely than women to develop high blood pressure. After age 55, women are more likely than men to develop high blood pressure.

Lifestyle Habits

Unhealthy lifestyle habits can raise your risk for high blood pressure, and they include:

Family History

A family history of high blood pressure raises the risk of developing prehypertension or high blood pressure. Some people have a high sensitivity to sodium and salt, which may increase their risk for high blood pressure and may run in families. Genetic causes of this condition are why family history is a risk factor for this condition.

What Are the Signs, Symptoms, and Complications of High Blood Pressure?

Because diagnosis is based on blood pressure readings, this condition can go undetected for years, as symptoms do not usually appear until the body is damaged from chronic high blood pressure.

Complications of High Blood Pressure

When blood pressure stays high over time, it can damage the body and cause complications. Some common complications and their signs and symptoms include:

Diagnosis of High Blood Pressure

For most patients, healthcare providers diagnose high blood pressure when blood pressure readings are consistently 140/90 mmHg or above.

Confirming High Blood Pressure

A blood pressure test is easy and painless and can be done in a healthcare provider's office or clinic. To prepare for the test:

To track blood pressure readings over a period of time, the healthcare provider may ask you to come into the office on different days and at different times to take your blood pressure. The healthcare provider also may ask you to check readings at home or at other locations that have blood pressure equipment and to keep a written log of all your results.

Blood Pressure Severity and Type

Your healthcare provider usually takes 2–3 readings at several medical appointments to diagnose high blood pressure. Using the results of your blood pressure test, your healthcare provider will diagnose prehypertension or high blood pressure if:

Once your healthcare provider determines the severity of your blood pressure, he or she can order additional tests to determine if your blood pressure is due to other conditions or medicines or if you have primary high blood pressure. Healthcare providers can use this information to develop your treatment plan.

Some people have “white coat hypertension.” This happens when blood pressure readings are only high when taken in a healthcare provider's office compared with readings taken in any other location. Healthcare providers diagnose this type of high blood pressure by reviewing readings in the office and readings taken anywhere else. Researchers believe stress, which can occur during the medical appointment, causes white coat hypertension.

How Is High Blood Pressure Treated?

Based on your diagnosis, healthcare providers develop treatment plans for high blood pressure that include lifelong lifestyle changes and medicines to control high blood pressure; lifestyle changes such as weight loss can be highly effective in treating high blood pressure.

Treatment Plans

Healthcare providers work with you to develop a treatment plan based on whether you were diagnosed with primary or secondary high blood pressure and if there is a suspected or known cause. Treatment plans may evolve until blood pressure control is achieved.

If your healthcare provider diagnoses you with secondary high blood pressure, he or she will work to treat the other condition or change the medicine suspected of causing your high blood pressure. If high blood pressure persists or is first diagnosed as primary high blood pressure, your treatment plan will include lifestyle changes. When lifestyle changes alone do not control or lower blood pressure, your healthcare provider may change or update your treatment plan by prescribing medicines to treat the disease.

If your healthcare provider prescribes medicines as a part of your treatment plan, keep up your healthy lifestyle habits. The combination of the medicines and the healthy lifestyle habits helps control and lower your high blood pressure.

Some people develop “resistant” or uncontrolled high blood pressure. This can happen when the medications they are taking do not work well for them or another medical condition is leading to uncontrolled blood pressure. Healthcare providers treat resistant or uncontrolled high blood pressure with an intensive treatment plan that can include a different set of blood pressure medications or other special treatments.

To achieve the best control of your blood pressure, follow your treatment plan and take all medications as prescribed. Following your prescribed treatment plan is important because it can prevent or delay complications that high blood pressure can cause and can lower your risk for other related problems.

Healthy Lifestyle Changes

Healthy lifestyle habits can help you control high blood pressure. These habits include:

To help make lifelong lifestyle changes, try making one healthy lifestyle change at a time and add another change when you feel that you have successfully adopted the earlier changes. When you practice several healthy lifestyle habits, you are more likely to lower your blood pressure and maintain normal blood pressure readings.

Medicines

Blood pressure medicines work in different ways to stop or slow some of the body's functions that cause high blood pressure. Medicines to lower blood pressure include:

To lower and control blood pressure, many people take two or more medicines. If you have side effects from your medicines, don't stop taking your medicines. Instead, talk with your healthcare provider about the side effects to see if the dose can be changed or a new medicine prescribed.

Prevention of High Blood Pressure

Healthy lifestyle habits, proper use of medicines, and regular medical care can prevent high blood pressure or its complications.

Preventing Worsening High Blood Pressure or Complications

If you have been diagnosed with high blood pressure, it is important to obtain regular medical care and to follow your prescribed treatment plan, which will include healthy lifestyle habit recommendations and possibly medicines. Not only can healthy lifestyle habits prevent high blood pressure from occurring, but they can reverse prehypertension and help control existing high blood pressure or prevent complications and long-term problems associated with this condition, such as coronary heart disease, stroke, or kidney disease.

Section 16.4: Stroke

This section contains text excerpted from the following sources: Text beginning with the heading “What Is a Stroke?” is excerpted from “Stroke,” National Heart, Lung, and Blood Institute (NHLBI), January 27, 2017; Text under the heading “What to Expect after a Stroke” is excerpted from “About Stroke—Recovering from Stroke,” Centers for Disease Control and Prevention (CDC), January 17, 2017.

What Is a Stroke?

A stroke occurs if the flow of oxygen-rich blood to a portion of the brain is blocked. Without oxygen, brain cells start to die after a few minutes. Sudden bleeding in the brain also can cause a stroke if it damages brain cells.

If brain cells die or are damaged because of a stroke, symptoms occur in the parts of the body that these brain cells control. Examples of stroke symptoms include sudden weakness; paralysis or numbness of the face, arms, or legs (paralysis is an inability to move); trouble speaking or understanding speech; and trouble seeing.

A stroke is a serious medical condition that requires emergency care. A stroke can cause lasting brain damage, long-term disability, or even death.

Types of Stroke

Ischemic Stroke

An ischemic stroke occurs if an artery that supplies oxygen-rich blood to the brain becomes blocked. Blood clots often cause the blockages that lead to ischemic strokes. The two types of ischemic stroke are thrombotic and embolic. In a thrombotic stroke, a blood clot (thrombus) forms in an artery that supplies blood to the brain.

 


Figure 16.3. Ischemic Stroke





Figure 16.3. Ischemic Stroke. The illustration shows how an ischemic stroke can occur in the brain. If a blood clot breaks away from plaque buildup in a carotid (neck) artery, it can travel to and lodge in an artery in the brain. The clot can block blood flow to part of the brain, causing brain tissue death.
Hemorrhagic Stroke

A hemorrhagic stroke occurs if an artery in the brain leaks blood or ruptures (breaks open). The pressure from the leaked blood damages brain cells. The two types of hemorrhagic stroke are intracerebral and subarachnoid. In an intracerebral hemorrhage, a blood vessel inside the brain leaks blood or ruptures. In a subarachnoid hemorrhage, a blood vessel on the surface of the brain leaks blood or ruptures. When this happens, bleeding occurs between the inner and middle layers of the membranes that cover the brain. In both types of hemorrhagic stroke, the leaked blood causes swelling of the brain and increased pressure in the skull. The swelling and pressure damage cells and tissues in the brain.

Who Is at Risk for a Stroke?

Certain traits, conditions, and habits can raise your risk of having a stroke or TIA. These traits, conditions, and habits are known as risk factors.

 


Figure 16.4. Hemorrhagic Stroke





Figure 16.4. Hemorrhagic Stroke. The illustration shows how a hemorrhagic stroke can occur in the brain. An aneurysm in a cerebral artery breaks open, which causes bleeding in the brain. The pressure of the blood causes brain tissue death.

The more risk factors you have, the more likely you are to have a stroke. You can treat or control some risk factors, such as high blood pressure and smoking. Other risk factors, such as age and gender, you can't control.

The major risk factors for stroke include:

Other risk factors for stroke, many of which of you can control, include:

Following a heart-healthy lifestyle can lower the risk of stroke. Some people also may need to take medicines to lower their risk. Sometimes strokes can occur in people who don't have any known risk factors.

What Are the Signs and Symptoms of a Stroke?

The signs and symptoms of a stroke often develop quickly. However, they can develop over hours or even days. The type of symptoms depends on the type of stroke and the area of the brain that's affected. How long symptoms last and how severe they are, vary among different people.

Signs and symptoms of a stroke may include:

A TIA has the same signs and symptoms as a stroke. However, TIA symptoms usually last less than 1–2 hours (although they may last up to 24 hours). A TIA may occur only once in a person's lifetime or more often. At first, it may not be possible to tell whether someone is having a TIA or stroke. All stroke-like symptoms require medical care.

Stroke Complications

After you've had a stroke, you may develop other complications, such as:

How Is a Stroke Diagnosed?

Your doctor will diagnose a stroke based on your signs and symptoms, your medical history, a physical exam, and test results. Your doctor will want to find out the type of stroke you've had, its cause, the part of the brain that's affected, and whether you have bleeding in the brain. If your doctor thinks you've had a TIA, he or she will look for its cause to help prevent a future stroke.

Medical History and Physical Exam

Your doctor will ask you or a family member about your risk factors for stroke. Examples of risk factors include high blood pressure, smoking, heart disease, and a personal or family history of stroke. Your doctor also will ask about your signs and symptoms and when they began.

Your doctor will look for signs of carotid artery disease, a common cause of ischemic stroke. He or she will listen to your carotid arteries with a stethoscope. A whooshing sound called a bruit may suggest changed or reduced blood flow due to plaque buildup in the carotid arteries.

Diagnostic Tests and Procedures

Your doctor may recommend one or more of the following tests to diagnose a stroke or TIA.

Brain Computed Tomography

A brain computed tomography scan, or brain CT scan, is a painless test that uses X-rays to take clear, detailed pictures of your brain. This test often is done right after a stroke is suspected. A brain CT scan can show bleeding in the brain or damage to the brain cells from a stroke. The test also can show other brain conditions that may be causing your symptoms.

Magnetic Resonance Imaging (MRI)

An MRI uses magnets and radio waves to create pictures of the organs and structures in your body. This test can detect changes in brain tissue and damage to brain cells from a stroke. An MRI may be used instead of, or in addition to, a CT scan to diagnose a stroke.

Computed Tomography Arteriogram (CTA) and Magnetic Resonance Arteriogram (MRA)

A CTA and an MRA can show the large blood vessels in the brain. These tests may give your doctor more information about the site of a blood clot and the flow of blood through your brain.

Carotid Ultrasound

Carotid Angiography

Carotid angiography is a test that uses dye and special X-ray to show the insides of your carotid arteries. For this test, a small tube called a catheter is put into an artery, usually in the groin (upper thigh). The tube is then moved up into one of your carotid arteries. Your doctor will inject a substance (called contrast dye) into the carotid artery. The dye helps make the artery visible on X-ray pictures.

Heart Tests

Electrocardiogram (EKG)

An EKG is a simple, painless test that records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through each part of the heart. An EKG can help detect heart problems that may have led to a stroke. For example, the test can help diagnose atrial fibrillation or a previous heart attack.

Echocardiography

Echocardiography, or echo, is a painless test that uses sound waves to create pictures of your heart. The test gives information about the size and shape of your heart and how well your heart's chambers and valves are working. Echo can detect possible blood clots inside the heart and problems with the aorta. The aorta is the main artery that carries oxygen-rich blood from your heart to all parts of your body.

Blood Tests

Your doctor also may use blood tests to help diagnose a stroke. A blood glucose test measures the amount of glucose (sugar) in your blood. Low blood glucose levels may cause symptoms similar to those of a stroke. A platelet count measures the number of platelets in your blood. Blood platelets are cell fragments that help your blood clot. Abnormal platelet levels may be a sign of a bleeding disorder (not enough clotting) or a thrombotic disorder (too much clotting).

How Is a Stroke Treated?

Treatment for a stroke depends on whether it is ischemic or hemorrhagic. Treatment for a TIA depends on its cause, how much time has passed since symptoms began, and whether you have other medical conditions.

Strokes and TIAs are medical emergencies. If you have stroke symptoms, call 9–1–1 right away. Do not drive to the hospital or let someone else drive you. Call an ambulance so that medical personnel can begin lifesaving treatment on the way to the emergency room. During a stroke, every minute counts. Once you receive immediate treatment, your doctor will try to treat your stroke risk factors and prevent complications by recommending heart-healthy lifestyle changes.

Treating an Ischemic Stroke or Transient Ischemic Attack (TIA)

An ischemic stroke or TIA occurs if an artery that supplies oxygen- rich blood to the brain becomes blocked. Often, blood clots cause the blockages that lead to ischemic strokes and TIAs. Treatment for an ischemic stroke or TIA may include medicines and medical procedures.

Medicines

If you have a stroke caused by a blood clot, you may be given a clot-dissolving, or clot-busting, medication called tissue plasminogen activator (tPA). A doctor will inject tPA into a vein in your arm. This type of medication must be given within 4 hours of symptom onset. Ideally, it should be given as soon as possible. The sooner treatment begins, the better your chances of recovery.

If you can't have tPA for medical reasons, your doctor may give you antiplatelet medicine that helps stop platelets from clumping together to form blood clots or anticoagulant medicine (blood thinner) that keeps existing blood clots from getting larger. Two common medicines are aspirin and clopidogrel.

Medical Procedures

Treating a Hemorrhagic Stroke

A hemorrhagic stroke occurs if an artery in the brain leaks blood or ruptures. The first steps in treating a hemorrhagic stroke are to find the cause of bleeding in the brain and then control it. Unlike ischemic strokes, hemorrhagic strokes aren't treated with antiplatelet medicines and blood thinners because these medicines can make bleeding worse.

If you're taking antiplatelet medicines or blood thinners and have a hemorrhagic stroke, you'll be taken off the medicine. If high blood pressure is the cause of bleeding in the brain, your doctor may prescribe medicines to lower your blood pressure. This can help prevent further bleeding.

Surgery also may be needed to treat a hemorrhagic stroke. The types of surgery used include aneurysm clipping, coil embolization, and arteriovenous malformation (AVM) repair.

Aneurysm Clipping and Coil Embolization

If an aneurysm (a balloon-like bulge in an artery) is the cause of a stroke, your doctor may recommend aneurysm clipping or coil embolization.

Aneurysm clipping is done to block off the aneurysm from the blood vessels in the brain. This surgery helps prevent further leaking of blood from the aneurysm. It also can help prevent the aneurysm from bursting again. During the procedure, a surgeon will make an incision (cut) in the brain and place a tiny clamp at the base of the aneurysm. You'll be given medicine to make you sleep during the surgery. After the surgery, you'll need to stay in the hospital's intensive care unit for a few days.

Arteriovenous Malformation Repair

If an AVM is the cause of a stroke, your doctor may recommend an AVM repair. (An AVM is a tangle of faulty arteries and veins that can rupture within the brain.) AVM repair helps prevent further bleeding in the brain.

Doctors use several methods to repair AVMs. These methods include:

How Can a Stroke Be Prevented?

Taking action to control your risk factors can help prevent or delay a stroke. If you've already had a stroke. Talk to your doctor about whether you may benefit from aspirin primary prevention, or using aspirin to help prevent your first stroke. The following heart-healthy lifestyle changes can help prevent your first stroke and help prevent you from having another one.

If you or someone in your family has had a stroke, be sure to tell your doctor. By knowing your family history of stroke, you may be able to lower your risk factors and prevent or delay a stroke. If you've had a TIA, don't ignore it. TIAs are warnings, and it's important for your doctor to find the cause of the TIA so you can take steps to prevent a stroke.

What to Expect after a Stroke

If you have had a stroke, you can make great progress in regaining your independence. However, some problems may continue:

Stroke Rehabilitation

Rehab can include working with speech, physical, and occupational therapists.

Therapy and medicine may help with depression or other mental health conditions following a stroke. Joining a patient support group may help you adjust to life after a stroke. Talk with your healthcare team about local support groups, or check with an area medical center.

Support from family and friends can also help relieve fear and anxiety following a stroke. Let your loved ones know how you feel and what they can do to help you.

Preventing Another Stroke

If you have had a stroke, you are at high risk for another stroke:

That's why it's important to treat the causes of stroke, including heart disease, high blood pressure, atrial fibrillation (fast, irregular heartbeat), high cholesterol, and diabetes. Your doctor may prescribe you medicine or tell you to change your diet, exercise, or adopt other healthy lifestyle habits. Surgery may also be helpful in some cases.

  This information is not a tool for self-diagnosis or a substitute for professional care.