Stress and Stress-Related Illness

Stress is a physical and/or emotional response to a difficult, painful, or challenging experience; it may affect children, teenagers, and adults. Stress-related illnesses are physical or mental disorders that may be brought on or made worse by stress.

What Is Stress?


Hans Selye (1907–1982) is considered the founder of modern stress research. He authored 39 books, wrote more than 1,700 scholarly papers, and was cited as a source in more than 362,000 scientific papers and countless articles in magazines and newspapers around the world. He also established the International Institute on Stress at the University of Montreal (now called the Canadian Institute of Stress and located in Toronto). The body's general adaptation syndrome is often called Selye syndrome.

Selye defined stress as “the nonspecific response of the body to any demand,” which means the body's reaction to any change in its environment. Selye linked physical illnesses not just to bacterial and viral infections but also to hormones within the body that are activated whenever the body responds to such external stressors as temperature extremes, pain, and threats to safety. Selye determined that many of the body's hormonal responses to stress are helpful and adaptive (positive change in response to environment), but others are maladaptive (unhelpful change) and place physical demands on the body that could result in disease.

Still, Selye described stress as the spice of life; it might make one person sick while invigorating another. In one of his bestselling books, The Stress of Life, Selye offered this rhymed advice: “Fight for your highest attainable aim/But never put up resistance in vain.” When people choose wisely about investing their efforts and emotional energy, they reduce the damaging side effects of stress; keep distress to a minimum; and increase their enjoyment of life.

What Causes Stress?


Stressors are the specific triggers of the body's stress response. These triggers are unique to each person. An event that one person finds relaxing may create tension in another. Stressors fall into several different categories:

Anxiety and excitement

Stress is often associated with negative thoughts or events that people find unpleasant, frightening, or anxiety-producing. It may come about as a result of being bullied or teased by peers, being anxious about a test, feeling disappointed about not achieving a goal, or trying to bundle too many activities into too little time. Sometimes life events that cause stress lead to initial anxiety that turns instead into positive excitement. An audition, a game point, or a date to the prom are positive stressors. Stress is the body's natural response to the difficult demands or exciting new challenges it encounters everyday.


Some events are so stressful that they overwhelm people, and no amount of deep breathing or positive thinking may help. Accidents, natural disasters, injuries, abuse, violence, war, serious threats to physical safety, or the sudden death of a loved one are examples of traumas that cause stress responses within the body.

Which Illnesses Are Linked to Stress?

It is difficult for researchers to establish a definite cause-and-effect relationship between stress and specific physical symptoms or illnesses. Not only do people's minds and bodies react differently to stress, but there are also other factors at work when someone gets sick. The following conditions are known or believed to be related to stress (as opposed to those caused by stress):

What Is the Stress Response?

Stressors, both good and bad, set off a series of events within the body's neuroendocrine (NUR-o-en-DO-krin) system. Often called the fight or flight response, these events are triggered by the brain, which alerts the body's autonomic nervous system * to prepare all systems to react to an emergency. The autonomic nervous system sends a message in a split second through nerve fibers that signal all the other body systems.

The body's stress hormone response. When the brain perceives stress, the hypothalamus releases corticotropin-releasing factor (1), which triggers the release of adrenocorticotropin (ACTH) (2) from the pituitary gland.

The body's stress hormone response. When the brain perceives stress, the hypothalamus releases corticotropin-releasing factor (1), which triggers the release of adrenocorticotropin (ACTH) (2) from the pituitary gland. ACTH (2) travels through the bloodstream and (along with signals from the brain sent through the autonomic nervous system) stimulates the adrenal glands to release cortisol and epinephrine into the bloodstream (3). Cortisol and epinephrine (3) help provide energy, oxygen, and stimulation to the heart, the brain, and other muscles and organs (4) to support the body's response to stress. When the brain perceives that the stress has ended, it allows hormone levels to return to their baseline values.
Illustration by Frank Forney. © 2016 Cengage Learning®.

During this alarm period, various hormones *

What Is Stress-Response Syndrome?

While psychiatrists have identified post-traumatic stress disorder (PTSD) and acute stress disorder (ASD) as specific mental illnesses ever since the 1970s, they have had some difficulty classifying a third type of stress-related problem known as adjustment disorder. This term was used as a catchall category for people who did not meet the diagnostic criteria for major depression or PTSD, but were clearly having difficulty coping with a specific major life stressor, such as a death in the family or job loss. Adjustment disorders were known to affect children and teenagers as well as adults, and often resulted from such stressors as changing schools or having trouble in school.

When the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) was replaced by DSM-5 in 2013, adjustment disorders were redefined as stress-response syndromes; that is, as simple responses to some type of life stress, which may or may not be a traumatic or catastrophic event.

Common Reactions to a Stressful Event

Common Reactions to a Stressful Event
SOURCE: Injury Prevention and Control, Division of Violence Protection, Centers for Disease Control and Prevention. “Coping with Stress.” Available at: (accessed July 13, 2016). Table by Cenveo Publisher Services. © 2016 Cengage Learning®.
Coping with Stress

Tips for coping with stress include the following:

  • Be realistic.
  • Don't try to be perfect.
  • Don't expect others to be perfect.
  • Take one thing at a time.
  • Be flexible.
  • Share feelings.
  • Maintain a healthful lifestyle.
  • Meditate.
  • Ask for help when necessary.
  • Keep a sense of humor.

Tips for helping others cope with stress include the following:

  • Pay attention.
  • Take the other person's concern seriously.
  • Be patient.
  • Offer help when necessary.

About 20 percent of Americans receiving outpatient mental health treatment are diagnosed with adjustment disorder/stress-response syndrome, according to the American Psychiatric Association. Treatment for this condition usually includes short-term psychotherapy as well as medications. It is important to note, however, that adolescents diagnosed with an adjustment disorder/stress-response syndrome are at higher risk than adults of being diagnosed with major depression or another severe mental disorder within the next five years.

What Are the Effects of Stress?

Researchers have found that chronic * stress and post-traumatic stress can suppress the immune system * , interfering with the body's natural ability to defend itself against infection. Chronic stress may also contribute to many other problems of mind and body, including:

Long-term stress (chronic stress), frequently recurring stress, or extreme stress from a life-threatening event can keep the body's stress response system activated for a long time. Long-term stress may lead to emotional or behavioral problems, post-traumatic stress disorder, or the development of stress-related illnesses. Chronic stress is believed to be a factor in many cases of abuse, violence, and suicide. Over the long term, chronic stress may contribute to the development of such cardiovascular problems as high blood pressure, heart disease, and stroke * . People who experience chronic stress can benefit from working with a doctor or therapist to learn stress management techniques.

How Is Stress Treated?

The treatment for stress is relaxation, leading to a state of ease, rest, and repose within the body. Taking a deep breath almost always is the first step toward relaxation, allowing individuals to recognize that the emergency that triggered the body's stress response has ended.

Relaxation response

At the end of a stress response cycle, the body begins to relax: Breathing slows down, the heart stops racing, muscles loosen, the mind becomes peaceful, and levels of stress hormones return to their baseline values. In addition to the body's automatic relaxation, people can consciously choose to use various techniques to achieve a relaxation response. Some people listen to music or sing, go for a long walk or a run in the park, or practice meditation. Other techniques and approaches that promote a relaxation response include yoga, abdominal breathing, progressive muscle relaxation, biofeedback * , guided imagery or visualization, hypnosis * , prayer, attending support groups, or spending time with pets or loved ones. Because stress is an inevitable part of living, the long-term antidote for stress is learning to use coping strategies that make it possible to live with stress successfully.


Resilient people who experience high levels of stress but recover quickly and show low levels of illness are said to have stress-resistant personalities. According to researchers, such resilient people seem to have several characteristics in common:

Some people seem to be born with resilient personalities and good stress management skills. They know instinctively how to manage and how to find the help they need from others. However, at times when a even a resilient person needs additional support, or when a person needs some coaching to improve coping skills, it may be useful to turn to a doctor, counselor, or therapist.

See also Addiction • Alcoholism • Allergies • Anxiety and Anxiety Disorders: Overview • Asthma • Depressive Disorders: Overview • Eating Disorders: Overview • Fears and Phobias • Headache • Heart Disease: Overview • Hypertension • Insomnia • Panic Disorder • Post-Traumatic Stress Disorder (PTSD) • Repetitive Stress Syndrome • Sleep Disorders: Overview • Suicide • Trauma


Books and Articles

Daitch, Carolyn, and Lissah Lorberbaum. The Road to Calm Workbook: Life Changing Tools to Stop Runaway Emotions. New York: W.W. Norton, 2016.

McGonigal, Kelly. The Upside of Stress: Why Stress is Good for You, and How to Get Good at It. 2nd ed. London: Avery, 2015.


Centers for Disease Control and Prevention. “Coping with Stress.” (accessed July 13, 2016).

National Institute of Mental Health. “Fact Sheet on Stress.” (accessed July 13, 2016).


American Heart Association. 7272 Greenville Ave., Dallas, TX 75231. Toll-free: 800-AHA-USA-1. Website: (accessed July 13, 2016).

American Institute of Stress. 6387B Camp Bowie Blvd. #334, Fort Worth, TX 76116. Telephone: 682-239-6823 Website: (accessed July 13, 2016).

American Psychological Association. 750 First St. NE, Washington, DC 20002-4242. Toll-free: 800-374-2721. Website: (accessed July 13, 2016).

* cancer is a condition characterized by the overgrowth of abnormal cells, which may be fatal.

* asthma (AZ-mah) is a condition in which the airways of the lungs repeatedly become nar-rowed and inflamed, causing breathing difficulty.

* eating disorders are conditions in which a person's eating behaviors and food habits are so unbalanced that they cause physical and emotional problems.

* schizophrenia (skit-so-FREE-nee-ah) is a serious mental disorder that causes people to experience hallucinations, delusions, and other thought disorders that cause them to lose touch with reality.

* autonomic nervous system is the part of the nervous system that acts largely unconsciously and controls such functions as heart rate, breathing rate, digestion, and urination.

* hormone is a chemical substance that is produced by a gland and sent into the bloodstream carrying messages that have specific effects on other parts of the body.

* chronic (KRAH-nik) means lasting a long time or recurring frequently.

* immune system is the system of the body composed of specialized cells and the substances they produce that helps protect the body against disease-causing germs.

* stroke is a brain-damaging event usually caused by interference with blood flow to the brain. A stroke may occur when a blood vessel supplying the brain becomes clogged or bursts, depriving brain tissue of oxygen. As a result, nerve cells in the affected area of the brain, and the specific body parts they control, do not function properly.

* biofeedback is a technique that helps people gain some voluntary control over normally involuntary body functions

* hypnosis is a trance-like state, usually induced by another person. The person under hypnosis may recall forgotten or suppressed memories and be unusually responsive to suggestions

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