A physician can determine the cause of the symptoms through a variety of methods. First, the physician will obtain a complete medical history, including any family history of cancer, symptoms, risk factors and other related medical information.

Following the history, the physician will conduct a complete physical examination with emphasis on the areas with the symptoms. A thorough examination of the head and neck region will be conducted, searching for any signs of abnormalities in the face and neck region.

Additional tests may be ordered by the physician to clearly diagnose the condition. These tests include:

• Endoscopy. A thin lighted tube called an endoscope is used to examine areas inside the body, in this case, the mouth, nasal cavities or throat. A laryngoscope is used to view the larynx and an esophagoscope is used to view the esophagus.
  
  
• Laboratory tests. Blood tests are used to gain information about the general physical condition of an individual. The tests may show malnutrition, low red blood cell count (anemia) or chemical abnormalities suggesting organ involvement.
  
  
• X-rays. Images taken of the head and neck on film that allow a physician to view abnormalities such as growths and tumors.
  
  
• CAT scan.  A series of images of inside the head and neck created by a scanner and computer. These pictures allow a physician to view a cross-sectional picture of the region of concern. The test may be done with or without dye contrast material. CAT scans can help determine the size, shape and position of a tumor as well as enlarged lymph nodes.

• Magnetic resonance imaging (MRI). A machine that uses a powerful magnet, radio waves and a computer to create detailed images of areas inside the head and neck. These pictures allow a physician to view the region in a three-dimensional view for any abnormalities.
  
  
• PET scan. A special radioactive sugar substance is injected into the vein and the body is viewed by a scanner. Cancer cells absorb the substance and the cancer area appears as a dark area on a screen. Recent research has shown that combined use of PET scans with CAT scans can improve detection of head and neck cancers and help determine the cancer's stage.
  
  
• Barium swallow. This test is a series of x-rays taken after the patient has swallowed a liquid containing the chemical barium. The test allows the physician to view the structures and functioning of the mouth, throat and esophagus. A modified version of this test can be used to diagnose any swallowing difficulties.
  
  
• Biopsy. A removal of tissue from the concerned area. The tissue is examined under a microscope by a pathologist for evidence of cancer cells. A biopsy is the only definitive way to diagnose cancer.

If the individual is diagnosed with cancer, the physician will need to learn the stage of the cancer. This stage provides information as to the extent of the damage and whether the cancer has spread to other areas of the body. Staging for head and neck cancers follows the American Joint Committee on Cancer for criteria.  Staging is different for each of the type of head and neck cancer and may involve additional biopsies or scans.