Throat Ulcers: Causes & Treatment Options

Medical review: Dr. Arthur Frazão
November 2021

A throat ulcer, or a throat canker sore, is a small, round sore that is whitish in the middle and reddish on the outside. It causes pain and discomfort, especially when swallowing or speaking. In some cases, it can be accompanied by other symptoms such as fever, general malaise and swollen lymph nodes in the neck area.

This type of ulcer may appear after ingesting acidic food, or it can be the first sign of a weakened immune system (e.g. appearing when you have herpes after a cold). When throat ulcers are very big and take a long time to heal, they can be a sign of a more serious disease such as AIDS or cancer.

The doctor may prescribe ointments for to treat a throat ulcer and suggest the elimination of acidic foods from your diet. Another common recommendation is gargling warm water with salt to help relieve discomfort.

What a throat canker sore looks like
What a throat canker sore looks like

Main causes

Throat ulcers may be caused by:

  • Weakened immune system, especially if weakened due to herpes (the herpes virus may infect the lining of both the mouth and throat)
  • Acidic foods, such as pineapple, tomato or pepper
  • Stomach problems, such as acid reflux
  • Nutrient deficiency, like B-complex vitamin, folic acid or minerals like iron

If you get a throat ulcer more than once a month, or if two outbreaks of ulcers happen within less than a week of each other, you should see your family doctor for blood tests that can help identify what may be causing the problem. Once the diagnosis is made, appropriate treatment is started so as to prevent the sore from appearing again.

Other situations that may cause small sores in the throat are tonsil stones, tonsillitis, and aphthous stomatitis, which are more common in infants.

Common treatment

Treatment for throat ulcers can be completed with combination corticosteroid and anti-inflammatory ointments, or with topical anesthetics (e.g. xylocaine 5%). These are prescribed by a doctor and applied with a finger or with the help of a cotton swab.

Other drugs that can be used to relieve pain caused by throat ulcers are acetaminophen or ibuprofen, and should be used as recommended by a doctor. Laser treatments can be used if the throat sore is greater than 1 cm in diameter or if the sore is causing difficulty with eating or drinking.

Speed-up throat ulcer healing

To help heal throat ulcers, some precautions should be considered, such as:

  • Rinsing your mouth with mouthwash after brushing your teeth, as this can help to eliminate bacteria and cleanse the area
  • Avoiding acidic foods like lemon, pineapple, tomato, kiwi and orange, as the acidity can increase pain
  • Eating more foods rich in B complex vitamins, folic acid and iron such as banana, mango, low-fat yogurt or apple juice (vitamin deficiency can cause throat ulcers)
  • Gargling warm water with salt or gargling hydrogen peroxide diluted in water, as they are antiseptic and clean the area. To prepare the solution, simply add 1 tablespoon of salt into 1 cup of warm water or 2 tablespoons of hydrogen peroxide 10 volumes in 1 glass of water.
  • Avoid worsening by not eating hard or crunchy foods such as toast, peanuts, nuts
  • Using a toothbrush with soft bristles;
  • Avoid oral hygiene products with irritating ingredients like sodium lauryl sulphate.

If you follow treatment as directed by your doctor while keeping these recommendations in mind, throat ulcers will likely disappear on their own within a few days.

When to go to the doctor

When throat ulcers appear frequently (e.g. more than 6 times a year) you should see a doctor for assessment, especially if you have other symptoms. Testing that may be ordered includes:

  • Complete blood count
  • Iron, ferritin and iron uptake, vitamin B12 levels
  • HIV antibodies, viral cultures and biopsy.

However, there is usually no need to request these exams and they are generally done when the throat ulcers are difficult to control.

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Atualizado por Tua Saude editing team, em November de 2021. Medical review por Dr. Arthur Frazão - Opthalmologist, em January de 2019.


  • BIBLIOTECA VIRTUAL EM SAÚDE (MINISTÉRIO DA SAÚDE). Aftas. 2015. Available on: <>. Access in 30 Mar 2020
  • SEMINÁRIOS FORL. Estomatites. Available on: <>. Access in 30 Mar 2020
Show more references
  • TELESSAUDERS UFRGS. ULCERAÇÃO AFTOSA RECORRENTE. Available on: <>. Access in 30 Mar 2020
Medical review:
Dr. Arthur Frazão
General practitioner
General practitioner, who completed at a specialty ophthalmology at the UFRN in 2008. Licensed to practice under CRM-PE license #16878.