The painful mouth sores can occur at any age but they are more common between the age of 10 and 40. Canker sores
are more common among women. These can be caused by oral trauma. Eating very hot or cold, spicy or acidic food can also cause canker sores.

Chewing tobacco and ill fitted dentures can also cause canker sores. Broken teeth with sharp edges can also cause these. Deficiency of vitamins and hormonal changes can also cause these sores. stress is also among a probable cause.