The short answer
A sore that does not heal — on the skin, or in the mouth — can be a warning sign of skin or oral cancer. Most sores heal on their own, but one that lasts more than a few weeks should be checked.
A sore that does not heal can be a warning sign of skin or mouth cancer.
Skin sores that do not heal can be a sign of skin cancer.
A mouth sore or white or red patch that lasts can be a sign of oral cancer, especially with tobacco use.
Most sores heal on their own within a couple of weeks.
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The full explanation.
The simple version
Most sores — a cut, a canker sore, a scrape — heal on their own within a couple of weeks. A sore that does not heal, or keeps coming back in the same place, can occasionally be a warning sign of skin or mouth cancer, and is worth checking.
What it can signal
A skin sore that does not heal can be a sign of skin cancer. In the mouth, a sore that lasts, or a white or red patch that does not go away, can be a sign of oral cancer — especially in people who use tobacco or drink heavily.
A sore that has not healed after a few weeks should be checked.
Most sores are harmless
The large majority of sores come from minor injuries, infections, or irritation and heal on their own. A doctor or dentist can check one that lingers.
When to see a doctor
See a doctor or dentist for a sore that has not healed after about three weeks, or a mouth patch that does not go away, especially if you use tobacco or alcohol.
Words to know
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Common questions
▸When is a non-healing sore a concern?
Most sores heal within a couple of weeks. A sore that has not healed after about three weeks, or that keeps coming back in the same spot, is worth checking.
▸Which cancers cause non-healing sores?
A skin sore that does not heal can be a sign of skin cancer. A mouth sore, or a white or red patch that lasts, can be a sign of oral (mouth) cancer, especially in people who use tobacco or alcohol heavily.
▸What else causes sores?
Most sores come from minor injuries, infections, or irritation and heal on their own. A doctor or dentist can check a sore that lingers.
▸When should I see a doctor?
See a doctor or dentist for a sore that has not healed after a few weeks, or a mouth patch that does not go away, especially with tobacco use.
Questions to ask your doctor
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