A canker sore is a little ulcer in the protective lining of your mouth. Unlike cold sores, which are caused by the herpes virus, canker sores are not the result of viral or bacterial infections and are not contagious.
Canker sores are caused by:
Injuries to the mouth, as seen frequently by contact sports players. Accidentally biting the inside of the cheek or lip may also result in a canker sore
Temperature - hot food or drink may cause a canker sore in the area of the mouth that was essentially burnt by the offending substance
Spicy and/or acidic foods often produce a canker sore as a response to the irritation these spices and acids create in the mouth
- The use of chewing (smokeless) tobacco will often cause a canker sore to develop in the area of the mouth where the tobacco is held, due to the irritating chemicals found in the addictive product
- Poor-fitting, complete or partial dentures may cause canker sores in the area of the mouth where the denture may rubbing on the tissue. The development of a canker sore is often one of the first signs that indicate the need for a denture reline or adjustment by your dentist
Canker sores usually appear on the inner surface of the cheeks and lips, tongue, upper surface of the mouth, and the base of the gums.
- One or more painful, red spots or bump that develops into an open ulcer
- White or yellow center
- Small size (most often under 1/3 inch across)
- Gray color as healing starts
- Less common symptoms include:
- General discomfort or uneasiness (malaise)
- Swollen lymph nodes
Pain often goes away in 7 to 10 days. It can take 1 to 3 weeks for a canker sore to completely heal. Large ulcers can take longer to heal.
You can treat your canker sore with various home remedies, such as:
Do you need to see a doctor?
If you feel very uncomfortable, a doctor will typically prescribe a topical steroid to quell the inflammatory response. Generally, if a lesion lingers more than two weeks, get it checked.