I Have a Red Sore on My Mouth β Is It Cancer?
Finding a red sore in your mouth can be alarming.
Most red sores in the mouth are not cancer. The most common causes are:
- Canker sores (aphthous ulcers) β small, painful red or white sores that usually heal within 1β2 weeks
- Injury β accidentally biting your cheek, a sharp food edge, or a rough filling
- Irritation β hot foods, braces, or dentures rubbing against the tissue
- Cold sores β caused by the herpes simplex virus, typically on the lips or around the mouth
- Allergic reaction β to certain foods, toothpaste, or mouthwash
However, a red sore that does not heal within 2β3 weeks should be examined by a dentist or doctor.
What to Look For
- Usually not serious (common causes):
- Sore appears after biting your cheek or eating something sharp
- Heals within 10β14 days
- Is painful (canker sores often hurt, which actually makes them less likely to be cancer)
- Has a clear white or yellow center with red border (typical canker sore)
- Worth having checked (less common but important):
- Sore that lasts more than 2β3 weeks without healing
- Red or reddish-white patch that does not go away
- Bleeding from the sore without obvious cause
- Hard or firm area around the sore
- Sore that is getting larger over time
When to See a Doctor
- See a dentist or doctor if:
- The sore has not healed after 2 weeks
- The sore is growing in size
- You notice numbness in your lip or tongue
- You have other symptoms like a lump in your neck, trouble swallowing, or unexplained ear pain
- You have a history of smoking, heavy alcohol use, or HPV