The causes of dysphagia may be diagnosed by a physician during a physical examination that includes a medical history. Patients may also be referred to an otolaryngologist (ear, nose and throat specialist) and a gastroenterologist (a physician who specializes in the function and disorders of the digestive system).

During the physical examination, the physician will perform a thorough inspection of the mouth and pharynx (throat) to check for signs of inflammation or tenderness and the presence of ulcers (lesions). The back of the patient’s throat may be swabbed with sterile cotton near the tonsils for laboratory analysis (throat culture). This test can detect the presence of bacteria, which indicates an infection.

The physician may administer a few ounces of water to the patient and observe while it is consumed. Sometimes, the physician may also assess the patient’s ability to consume foods of various textures. During the evaluation of medical history, patients will typically be asked about their symptoms, diet, bowel habits and any prescription and/or over-the-counter medications they may be taking.

Diagnostic tests that may be conducted when a patient has dysphagia include:

• Modified barium swallow. During this test, a patient drinks a thick, white liquid called barium, which coats the digestive tract. The uppermost areas of the digestive tract including the mouth, throat and esophagus are then highlighted during x-rays to help diagnose the cause of dysphagia. The test can help reveal blockages, irregular growths, tumors and other potential abnormalities.
  
  
• Blood tests. Blood is drawn and tested for evidence of an infectious disease, anemia, thyroid condition or other disorders that may be causing the dysphagia.
  
  
• Endoscopy. Uses a tube equipped with a camera that allows a physician to view the inside of hollow organs or body cavities and locate the source of dysphagia. If necessary, a physician can use the endoscope to perform a biopsy.
  
  
• X-rays. Images of body parts, organs or bodily systems on film paper or fluorescent screens. These are produced by using low doses of radiation. Chest and neck x-rays can detect the presence of pneumonia (lung infection), a potential complication of dysphagia.
  
  
• Computed axial tomography (CAT) scan or magnetic resonance imaging (MRI). These imaging tests provide excellent definition of structural abnormalities such as growths of the throat, chest, esophagus and stomach.

• Esophageal pH monitoring. This is the most sensitive test to diagnose gastroesophageal reflux disease, if this condition is suspected of causing dysphagia. It involves passing a thin tube through the nose and into the esophagus. The tube is attached to a small monitoring device and is worn for 24 hours. The device records how much stomach acid reaches the esophagus. This is typically performed when an endoscopy is inconclusive or a patient continues to experience symptoms after receiving treatment.
  
  
• Esophageal manometry. If a physician suspects esophageal spasm or another esophageal motor disorder as the cause of dysphagia, this test may be ordered. During the procedure, a small tube is inserted into the esophagus and connected to a pressure recorder. This allows measurement of the muscle contractions of the esophagus while a patient swallows.