A red and inflamed throat from pharyngitis, an infection caused by Streptococcus bacteria.
CDC/Heinz F. Eichenwald, MD.
The pain and discomfort of a sore throat, also called pharyngitis (fair-un-JY-tis), are usually the result of inflammation due to infection or irritation. Strep throat is caused by bacteria * in the Streptococcus (strep-to-KOK-us) family. Its main symptoms are sore throat and fever. The medical term for strep throat is streptococcal pharyngitis.
A sore throat can be a symptom of many infectious diseases. Infections such as the common cold, influenza * , adenovirus * infections, and infectious mononucleosis * cause most sore throats. Bacterial infections are less common, but the sore throats they produce usually are more severe. Group A beta-hemolytic streptococci (he-muh-LIH-tik strep-tuh-KAH-kye) are the most common bacterial culprits, and they cause strep throat. Rarely, fungal infections can cause a sore throat, usually in people with a weakened immune system * . Noninfectious causes of sore throat include allergies, postnasal drip (the dripping of mucus from the back of the nose into the throat), and too much yelling or straining the voice. Smoking and other irritants can also cause a sore throat.
Sore throats are very common, especially in children. It is not unusual for children between five and 10 years old to develop several sore throat infections over the course of a year. Most of these illnesses are common viral respiratory infections. About 15 percent of all sore throats are caused by group A streptococci.
All of the infections that cause sore throats are contagious. They can spread through contact with drops of fluid from an infected person that can be coughed or sneezed into the air. The drops can be inhaled or transferred by the hand to the mouth or nose. The infections that cause sore throats also can spread through direct contact with an infected person, often through shaking hands or kissing.
Sore throats are painful, sometimes swollen, and red. Many viral infections that cause sore throats are associated with other symptoms, including hoarseness, runny nose, cough, and diarrhea * .
Sore throat is a common symptom of infectious mononucleosis, a viral infection caused by the Epstein-Barr (EP-steen BAR) virus. The tonsils * become very swollen and may have white patches or an extensive coating. Swallowing is difficult, and in a few cases, the tonsils enlarge enough to cause difficulty breathing. Other signs and symptoms of mononucleosis include swollen lymph nodes * in the neck, fever, extreme tiredness, muscle aches, and an enlarged spleen.
People with strep throat feel generally weak and tired. The tonsils often are enlarged and have white specks and pus * * pain.
If a patient's sore throat and other symptoms match those of a common viral cold or respiratory infection, the doctor may base the diagnosis on the physical symptoms alone. Nasal and throat swabs can be tested to detect other causes of a sore throat if necessary.
If the doctor suspects that a patient might have a strep throat infection, the doctor uses a cotton swab to take a sample from the throat and tonsils for a culture * . Often, the doctor will do a rapid strep test of the bacteria from the throat swab in the office. This quick test can give the doctor results in 10 to 15 minutes. A positive result indicates that strep bacteria are present; a negative result means that the strep bacteria may or may not be present and a more extensive culture should be done.
Infectious mononucleosis is diagnosed by examining blood samples for antibodies * to the virus.
Treatment of a sore throat depends on the diagnosis. If it stems from a common cold caused by a virus, treatment is aimed at relieving symptoms until the illness disappears. Drinking plenty of fluids can help prevent dehydration * and clear out mucus * in the back of the throat. Water, ginger ale, warm tea with honey, and clear soups are good choices, but not acidic juices (such as lemonade or orange juice) because they can irritate the throat. Gargling with warm salt water can help soothe a sore throat, and over-the-counter pain relievers and throat drops can ease symptoms as well. Antibiotics are not effective for treating viral infections such as colds. Most viral sore throats go away on their own without complications, and they generally clear up within a few days to a week.
The best treatment for infectious mononucleosis is rest. In addition, over-the-counter medications such as acetaminophen * can help relieve pain and fever. Studies have shown that one type of antiviral medication (valacyclovir) may be useful in reducing the severity of symptoms. Severe cases of infectious mononucleosis may benefit from the administration of corticosteroids * to reduce swelling and inflammation. Infectious mononucleosis can take from one to two months to subside, and other symptoms from the illness, such as tiredness, can remain for months afterward.
When strep throat has been diagnosed, a course of antibiotic *
Strep throat can lead to scarlet fever * , rheumatic fever * , kidney * problems, including post-streptococcal glomerulonephritis, or throat abscesses * . Prompt treatment with antibiotics can prevent most of these complications.
Many respiratory infections, both viral and bacterial, are spread through contact with respiratory fluids from infected people. People who have respiratory infections and sneeze or cough in a classroom, on a playground, or in another crowded environment can spread the infection to other people. Moisture droplets from their coughing or sneezing are passed into the air. Others inhale these germs, and then they too become infected.
Another way respiratory infections can be passed along is by hand-to-hand contact or by touching objects that an infected person has recently handled. That is why doctors tell people to wash their hands regularly. If someone has an infection or has been in close contact with someone who does, it is wise not to share utensils, food, and drinking glasses with that person.
See also Abscesses • Bacterial Infections • Common Cold • Fever • Fungal Infections • Glomerulonephritis • Infection • Influenza • Laryngitis • Mononucleosis, Infectious • Rheumatic Fever • Scarlet Fever • Streptococcal Infections • Tonsillitis • Viral Infections
Nordqvist, Christian. “What Is Strep Throat? What Is Sore Throat?” Medical News Today, September 15, 2014. http://www.medicalnewstoday.com/articles/155412.php (accessed July 11, 2016).
MedlinePlus “Sore Throat.” U.S. National Library of Medicine. https://www.nlm.nih.gov/medlineplus/sorethroat.html (accessed July 11, 2016).
National Institute of Allergy and Infectious Diseases. “Is It Strep Throat?” http://www.niaid.nih.gov/topics/strepthroat/pages/default.aspx (accessed July 11, 2016).
Wisconsin Department of Health Services. “Streptococcal Pharyngitis (Strep Throat).” https://www.dhs.wisconsin.gov/publications/p4/p42092.pdf (accessed July 11, 2016).
American Academy of Family Physicians. PO Box 11210, Shawnee Mission, KS 66207-1210. Toll-free: 800-274-2237. Website: http://www.aafp.org (accessed July 11, 2016).
American Osteopathic Association. 142 East Ontario St., Chicago, IL 60611-2864. Toll-free: 800-621-1773. Website: (accessed July 11, 2016).
Centers for Disease Control and Prevention. 1600 Clifton Rd., Atlanta, GA 30329-4027. Toll-free: 888-674-6854. Website: http://www.cdc.gov (accessed July 11, 2016).
* bacteria (bak-TEER-ee-a) are single-celled microorganisms, which typically reproduce by cell division. Some but not all types of bacteria can cause disease in humans. Many types can live in the body without causing harm.
* influenza (in-floo-EN-zuh), also known as the flu, is a contagious viral infection that attacks the respiratory tract, including the nose, throat, and lungs.
* adenovirus (ah-deh-no-VY-rus) is a type of virus that can produce a variety of symptoms, including upper respiratory disease, when it infects humans.
* mononucleosis (mah-no-nu-klee-O-sis) is an infectious illness caused by a virus with symptoms that typically include fever, sore throat, swollen glands, and tiredness.
* immune system (im-YOON) is the system of the body composed of specialized cells and the substances they produce that protect the body against disease-causing germs.
* diarrhea (di-ah-RE-a) refers to frequent watery stools (bowel movements).
* tonsils are paired clusters of lymphatic tissue in the throat that protect the body from bacteria and viruses that enter through a person's nose or mouth.
* lymph nodes (LIMF) are small bean-shaped masses of tissue containing immune system cells that fight harmful microorganisms.
* pus is a thick creamy fluid, usually yellow or ivory in color, that forms at the site of an infection. Pus contains infection-fighting white cells and other substances.
* abdominal (ab-DAH-mih-nul) refers to the area of the body below the ribs and above the hips that contains the stomach, intestines, and other organs.
* culture (KUL-chur) is a test in which a sample of fluid or tissue from the body is placed in a dish containing material that supports the growth of certain organisms. Typically, within days the organisms will grow and can be identified.
* antibodies (AN-tih-bah-deez) are protein molecules produced by the body's immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.
* dehydration (dee-hi-DRAY-shun) is a condition in which the body is depleted of water, usually caused by excessive and unreplaced loss of body fluids through sweating, vomiting, or diarrhea.
* mucus (MYOO-kus) is a thick, slippery substance that lines the interior of many body parts.
* acetaminophen (uh-see-tehMIH-noh-fen) is a medication commonly used to reduce fever and relieve pain.
* corticosteroids (kor-tih-ko-STIR-oyds) are chemical substances made by the adrenal glands that have several functions in the body, including maintaining blood pressure during stress and controlling inflammation. They can also be given to people as medication to treat certain illnesses
* antibiotic (an-tie-by-AH-tik) is a drug that kills or slows the growth of bacteria.
* scarlet fever is an infection that causes a sore throat and a rash.
* rheumatic fever (roo-MAH-tik) is a condition associated with fever, joint pain, and inflammation affecting many parts of the body, including the heart. It occurs following infection with certain types of strep bacteria.
* kidney is one of the pair of organs that filter blood and remove waste products and excess water from the body in the form of urine.
* abscesses (AB-seh-sez) are localized or walled off accumulations of pus caused by infection that can occur anywhere within the body.