Are cold sores and canker sores the same thing?
Cold sores are not the same as canker sores. Cold sores are a form of herpes, herpes simplex type 1. The sore is fluid-filled, painful, and located outside the mouth around the lips. These sores are also very contagious. Canker sores are ulcers that develop inside the mouth. These sores make eating and talking uncomfortable. They are typically caused by stress or an injury to the tissue inside the mouth.