what causes roof of mouth to become red?
Canker Sore-Canker sores can develop on the roof of the mouth. These can be caused by exposure to bacteria or when the tissue becomes damaged due to a scratch or burn. Canker sores will begin as a red mark on the roof of the mouth, but will slowly fill in with white or yellow pus.
At first, inflammation helps to heal the body or injured area. However, problems occur when your body is unable to repair itself and return to normal function. 1  An example of acute inflammation is when you burn the roof of your mouth with hot coffee. 2  The roof of your mouth is red, swollen, hot, and painful.