Canker sores and oral cancer lesions may seem similar but there are ways to tell the difference. A lesion that's red, typically flat, and painful early on is usually a canker sore (aphthous ulcer).

Causes of a sore throat on one side includes the flu, tonsillitis, a canker sore, or a tumor. Look out for other symptoms to help you identify what's causing your sore throat on one side.

Canker sores inside mouths are one of the most nagging problems that we humans can experience. The word canker comes from Latin cancer, but here it means an eroding/erosive ulcer that spreads out.