People sometimes confuse canker sores with cold sores, but they are completely unrelated. Both can be painful, but knowing the differences can help you manage them.

A canker sore typically occurs on the delicate tissues inside your mouth. It is usually light-colored at its base and can have a red exterior border.

On the other hand, a cold sore or fever blister usually occurs on the outside of the mouth, usually on or near the nose or lips. It is contagious because it is caused by the herpes simplex virus, and it is usually painful and filled with fluid.

In most cases, patience is the best medicine for treating canker sores. A healthy diet and good oral hygiene are usually the best remedies, but some special rinses and anesthetics can help. Cold sores can be treated effectively with some over-the-counter topical creams; sometimes, your doctor will prescribe an antiviral medication.