Gastroesophageal reflux disease (GERD) is usually diagnosed during a physical examination. Diagnosis is generally based on the patient's symptoms. A physician may try to rule out more serious conditions that may be causing symptoms. For example, a physician may try to rule out heart disease in a patient experiencing chest pain.

Patients exhibiting symptoms of GERD may be referred to a gastroenterologist (a physician who specializes in conditions and disorders of the gastrointestinal tract).

In cases where the diagnosis is unclear, some tests may be performed. They include:

• Endoscopy.  One of the most common tests used to evaluate the esophagus. A small tube with a light and camera (endoscope) is inserted into the esophagus, stomach and small intestine. This allows a physician to determine whether there is tissue damage. Samples of tissues may be taken (biopsy) to determine the extent of the damage.
  
  
• Barium swallow (upper GI series). A test in which an x-ray is taken after liquid barium is ingested. This can detect abnormalities and sometimes inflammation of the esophagus (esophagitis). However, it may not be useful in diagnosing some cases of GERD.
  
  
• Esophageal pH monitoring. This is the most sensitive test for diagnosing GERD. 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. There is a newer method that allows pH recording without the need for a tube through the nose called the Bravo device. The patient records symptoms experienced during the 24-hour period and the physician compares acid levels with symptoms. This is typically performed when an endoscopy is inconclusive or a patient continues to experience symptoms after receiving treatment.
  
  
• Esophageal manometry. Involves a device similar to the pH monitor that measures muscle contractions to determine whether the lower esophageal sphincter (LES) is functioning properly. This is typically performed when surgery is being considered.

The American College of Gastroenterology devised a test called the Richter Scale/Acid Test to help patients determine whether they may have GERD. Questions include:

1. Does the patient frequently have one or more of the following:
   
   
• An uncomfortable feeling behind the breastbone that seems to be moving upward from the stomach?
  
  
• A burning sensation in the back of the throat?
  
  
• A bitter acid taste in the mouth?
  
  
2. Does the patient often experience these symptoms after meals?
   
   
3. Does the patient experience heartburn or acid indigestion two or more times per week?
   
   
4. Does the patient find that antacids provide only temporary relief?
   
   
5. Does the patient experience symptoms even after taking prescription medication?

Patients who answer yes to two or more of the questions may have GERD and should consult a physician.