To diagnose your condition, your doctor will evaluate your medical history, perform a physical examination, and order tests. The physical examination may include visual inspection of your oral and nasal cavities, neck, throat, and tongue using a small mirror and/or lights. Your doctor may also feel for lumps on your neck, lips, gums, and cheeks. 

Examinations and tests will vary, depending on your symptoms. Common diagnostic tests and procedures include:

• Biopsy is the removal of tissue for examination. A pathologist studies the tissue under a microscope to make a diagnosis. A biopsy is the only sure way to tell whether a person has cancer.
• CT (CAT) scan is a series of detailed pictures of areas inside your head and neck created by a computer linked to an X-ray machine.
• Endoscopy is the use of a thin, lighted tube called an endoscope to examine areas inside the body. The type of endoscope the doctor uses depends on the area being examined. For example, a laryngoscope is inserted through the mouth to view the larynx; an esophagoscope is inserted through the mouth to examine the esophagus; and a nasopharyngoscope is inserted through the nose so the doctor can see the nasal cavity and nasopharynx.
• Laboratory tests examine samples of blood, urine, or other substances from the body.
• Magnetic resonance imaging (MRI) uses a powerful magnet linked to a computer to create detailed pictures of areas inside the head and neck.
• PET scan uses sugar modified in a specific way so that it is absorbed by cancer cells and appears as dark areas on the scan.
• X-rays create images of areas inside the head and neck on film.

If your diagnosis is cancer, your doctor will want to learn the stage, or extent, of the disease. Staging is a careful attempt to find out whether your cancer has spread and, if so, to which parts of your body. Staging may involve an examination under anesthesia in the operating room, X-rays and other imaging procedures, and laboratory tests. Knowing the stage of your head or neck cancer will help your doctor plan your treatment.