Tonsillitis: What Causes Swollen Tonsils?

Symptoms, Causes, and Treatments

Woman doctor examining sore throat.
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Your tonsils are a part of the lymphatic system, which is responsible for eliminating your body of toxins and harmful substances such as viruses and bacteria. Your tonsils trap inhaled particles, which are then transported to your lymphatic system to be disposed of by your immune system.

There are 3 pairs of tonsils in your body:

  • pharyngeal tonsils or adenoids: located at roof of your mouth where you nose connects to your throat
  • lingual tonsils: located behind the tongue
  • palatine tonsils: located at the back of the throat

When your tonsils become overwhelmed by the organisms they protect your body from, they become enlarged and swollen, a condition known as tonsillitis. Tonsillitis is a common problem and most children will experience at least one episode before reaching adulthood. Enlarged tonsils occur in people of all ages, but are most common in children ages 5 to 15 years old.


A sore throat is the common symptom and the biggest reason for seeking medical attention related to swollen tonsils. Other common symptoms include:

  • odynophagia (painful swallowing)
  • dysphagia (difficulty swallowing)
  • redness at the site of your tonsils
  • pockets or patches of white on the tonsils (known as exudates)
  • other lymph node enlargement
  • fever
  • headache
  • fatigue
  • petechiae, or small red or purple spots on the roof of your mouth

While there are many symptoms that can accompany enlarged tonsils, you are not likely to experience all of them.

Your doctor may suspect strep throat if you have enlarged tonsils, redness, a fever, and no cough. Other symptoms will help your doctor to identify other causes.


While the tonsils serve as a front-line defense from respiratory infections, occasionally the tonsils will actually become infected by the bacteria and viruses.

Bacterial infections only account for about 30 out of 100 cases of swollen tonsils.

Common infections that cause tonsillitis include:

Non-infectious causes of swollen tonsils are more rare, but may include:

Related Complications

Typically, the symptoms related to tonsillitis are just annoying, requiring no intervention. If you have a viral infection, which is often the case, no treatment is required. If your symptoms are bad enough, your doctor may prescribe you medications to treat your symptoms but will not provide you with an antibiotic if a virus is suspected.

Because complications of strep throat can be serious, you should see a doctor to have a strep test if you have swollen tonsils, especially if they are accompanied by redness and throat pain. Occasionally strep infections can become chronic and difficult to cure. Chronic strep infections sometimes make surgical removal of the tonsils necessary.

In some cases, tonsils may become so swollen that they may interfere with breathing or swallowing or cause obstructive sleep apnea.

Sleep apnea is a serious condition that causes a person to stop breathing for a brief period of time while sleeping. Studies have shown that sleep apnea can lead to daytime fatigue, depression, mood swings, and more serious health conditions including high blood pressure and heart disease. Obstructive sleep apnea is also a leading indication for tonsillectomies in the United States.


Swollen tonsils caused by bacterial infections can be treated with antibiotics. Symptoms usually go away within a few 24 hours after starting medication. Antiviral medications are not typically prescribed for most cases of swollen tonsils.

Antivirals unlike antibiotics  do not actually kill a viral infection but slow down the spreading of the virus. This allows your body to fight the viral infection.

In some cases it may be possible to reduce the size of your enlarged tonsils by taking an oral steroid. However, since steroid medications have many side-effects, most doctors are hesitant to prescribe these medications unless the tonsils are extremely swollen and bothersome. Your body's immune system in general will be sufficient to eliminate the virus and your tonsils will return to their normal size without any medications.

If you have persistent or frequent episodes of swollen tonsils that are impacting your quality of life, your doctor may recommend a tonsillectomy. By surgically removing your tonsils, any severe symptoms can typically be resolved. Before having a tonsillectomy your doctor will discuss the risks versus benefits for the surgery, given your circumstances.

Home Remedies to Try

If your doctor chooses not to treat your swollen tonsils with medication or surgery, there are still things you can do at home to help manage your sore throat:

  • Drink warm fluids like teas or soups with broth
  • Gargle warm salt water—add 1/4 to 1/2 teaspoon of salt to 8 ounces of water
  • Drink cold fluids or suck on popsicles
  • Suck on lozenges or hard candy
  • Use a throat spray that has benzocaine in it
  • Put an ice pack on your neck
  • Use a cool mist humidifier
  • Take over-the-counter pain relievers such as ibuprofen or acetaminophen (it's probably best to avoid aspirin, especially in children)

A Word From Verywell

Swollen tonsils are often personally concerning because of the impact they can have on your daily life. Your ability to drink and eat can become painful, for example.

If you do not have a fever, try some of the home remedies described above. However, if you do have a fever or swollen tonsils that have not resolved or are causing other difficulties, you need to see your doctor. Often, tonsils that are enlarged will resolve and shrink back to normal size on their own. Remember that bacterial infections only account for about 30 percent of the cases, so you may not be prescribed antibiotics in all cases.


Fact Sheet: Tonsillitis. American Academy of Otolaryngology - Head and Neck Surgery. Updated January 2011.

Tonsils and Adenoids. American Academy of Otolaryngology - Head and Neck Surgery.

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