Mouth ulcers


Mouth ulcers are sores or open lesions in the mouth.


Mouth ulcers are caused by many disorders. These include:

A skin sore caused by histoplasmosis may also appear as a mouth ulcer.


Symptoms will vary, based on the cause of the mouth ulcer. Symptoms may include:

Exams and Tests

Most of the time, a health care provider or dentist will look the ulcer and where it is in the mouth to make the diagnosis. You may need blood tests or a biopsy of the ulcer may be needed to confirm the cause.


The goal of treatment is to relieve symptoms.

Outlook (Prognosis)

The outcome varies depending on the cause of the ulcer. Many mouth ulcers are harmless and heal without treatment.

Some types of cancer may first appear as a mouth ulcer that does not heal.

Possible Complications

Complications may include:

When to Contact a Medical Professional

Call your health care provider if:


To help prevent mouth ulcers and complications from them:

Review Date: 1/31/2015
Reviewed By: Linda J. Vorvick, MD, medical director and director of didactic curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

This information should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. © 1997- 2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.