To diagnose the probability of mouth cancer, your doctor will begin by asking about your symptoms and the incidence of cancer in your family. You will then undergo a physical examination where the doctor will examine your affected area, particularly your oral cavity, for swelling and soreness and possible causes of the inflammation. He or she will use gloved fingers to feel for any lumps along the inside of your mouth. He or she will also conduct an indirect laryngoscopy, wherein they will examine the back of your throat using a mirror. The doctor will also feel for any swollen lymph nodes around the neck.
If ample evidence points towards cancer, you will be asked to have a biopsy for confirmation. Additionally, the doctor may also conduct a nasoendoscopy or panedoscopy, to look at your upper air passages through a tube inserted through your nose into the back of your throat.