Sore throat

A sore throat is pain or irritation of the throat. Swallowing often makes it feel worse. The most common cause of a sore throat, also called pharyngitis, is a viral infection, such as a cold or the flu. A sore throat from a virus goes away on its own.

Strep throat, also called a streptococcal infection, is a less common type of sore throat. Bacteria causes it. Strep throat needs treatment with antibiotics.

There are other less common causes of sore throat. They might need more treatment.

Take your child to a healthcare professional if the sore throat doesn't go away after taking a drink in the morning. This advice is from the American Academy of Pediatrics.

Get immediate care for a child who has severe symptoms such as:

• Trouble breathing.
• Not being able to swallow.
• Unusual drooling, which might be from not being able to swallow.

If you're an adult, see a healthcare professional for a sore throat and any of the following problems. This advice comes from the American Academy of Otolaryngology — Head and Neck Surgery:

• A bad sore throat that lasts longer than a week.
• Not being able to swallow.
• Trouble breathing.
• Trouble opening the mouth.
• Joint pain.
• Earache.
• Rash.
• Fever higher than 101 F (38.3 C).
• Bloody mucus.
• Repeated sore throats.
• A lump in the neck.
• Hoarseness that lasts more than two weeks.
• Swelling in the neck or face.

Viruses that cause the common cold and the flu also cause most sore throats. Less often, bacterial infections cause sore throats.

Viral infections

Many viral illnesses cause a sore throat such as:

• Common cold.
• Flu, also called influenza.
• Mono, also called mononucleosis.
• Measles.
• Chickenpox.
• Coronavirus disease 2019 (COVID-19).
• Croup, a common childhood illness that causes a harsh, barking cough.

Bacterial infections

Many bacterial infections can cause a sore throat. The most common bacterium that causes a sore throat is Streptococcus pyogenes, also called group A streptococcus. This bacterium causes strep throat and other illnesses. Strep throat is most common in school-age children and teens.

Other causes

Other causes of a sore throat include:

• Allergies. Allergic reactions can cause a sore throat. The reaction might be to molds, dust, pollen or flecks of skin shed by dogs, cats, and other animals with fur or feathers, also called pet dander. Mucus that builds up and drips down the back of the nose and throat, also called postnasal drip, can make a sore throat worse.
• Dryness. Dry indoor air can make the throat feel rough and scratchy. Breathing through the mouth also can cause a dry, sore throat. An ongoing stuffy nose can cause breathing through the mouth.
• Irritants. Irritants in outdoor and indoor air, also called air pollution, can cause an ongoing sore throat. These include tobacco smoke, chemicals and dust, pollen, and mold. Chewing tobacco, drinking alcohol and eating spicy foods also can irritate the throat.
• Muscle strain. Yelling, talking loudly or talking for a long time without rest can strain muscles in the throat.

• Gastroesophageal reflux disease (GERD). GERD causes stomach acid to back up in the food pipe, also called the esophagus.

  Other symptoms might include heartburn, hoarseness, stomach contents going back up the food pipe and the feeling of having a lump in the throat.

• HIV infection. A sore throat and other flu-like symptoms sometimes appear soon after someone is infected with HIV. Someone who is HIV-positive might have a constant sore throat or one that keeps coming back.
• Tumors. Cancerous tumors of the throat, tongue or voice box, also called the larynx, can cause a sore throat. Other symptoms might include hoarseness, trouble swallowing, noisy breathing, a lump in the neck and bloody mucus.

Rarely, an infected area of tissue, also called an abscess, in the throat can cause a sore throat. So can swelling of the flap that covers the windpipe during swallowing, also called the epiglottis. Either can block the airway, which is a medical emergency.

Anyone can get a sore throat. But some things make it more likely to get one, including:

• Being around tobacco smoke. Smoking and secondhand smoke can irritate the throat. The use of tobacco products also raises the risk of cancers of the mouth, throat and voice box.
• Allergies. People who have seasonal allergies or other allergic reactions are more likely to get a sore throat.
• Being around chemicals. Tiny bits in the air from burning fossil fuels and common household cleaners and other chemicals can cause throat irritation.
• Having sinus infections often. Mucus running down the throat from the nose can irritate the throat or spread infection.
• Being near other people. Viral and bacterial infections spread easily anywhere people get together. This includes child care centers, classrooms, offices, arenas and airplanes.
• Weak immune system. People whose immune system's defenses are low are more likely to get any kind of infection than are other people. Common causes of a weak immune system include HIV, diabetes, treatment with steroids or chemotherapy medicines, stress, fatigue, and poor diet.

The best way to prevent sore throats is to avoid the germs that cause them and to stay clean. Follow these tips and teach children to do the same:

• Wash hands often and well. Wash for at least 20 seconds, especially after using the toilet, before and after eating, and after sneezing or coughing.
• Avoid face touching. Don't touch eyes, nose or mouth.
• Don't share food, drinking glasses or forks, knives and spoons.
• Cough or sneeze into a tissue and throw it away. Then wash hands. If there's no tissue, sneeze into the elbow.
• Use hand cleansers, also called alcohol-based hand sanitizers. Do this to wash hands when there's no soap and water.
• Don't touch public phones or drinking fountains with the mouth.
• Often clean and disinfect phones, doorknobs, light switches, remotes and computer keyboards. On a trip, clean phones, light switches and remotes in the hotel room.
• Stay away from people who are sick or have symptoms.