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What is a pH study?

The stomach makes acid that aids in digestion of food. Acid reflux is movement of the acid into the esophagus. Sometimes patients have vague, odd, or atypical symptoms instead of classic burning chest discomfort. A trial of antacid medication can help sort this out if your symptoms go away with treatment. But other things can cause chest pain like heart or lung problems and can be very difficult to differentiate from acid reflux. Additionally, patients with acid reflux symptoms may be on a maximum amount of medication and still experience acid reflux-type symptoms.

A pH study measures the amount of acid present in the esophagus and how long it stays there. This helps determine when a patient actually has pain or discomfort and the amount of acid in the esophagus to see if they correlate. When you experience heartburn and the pH test shows acid, then true acid reflux is present. But frequently people may have heartburn symptoms with no acid — this is not acid reflux and may need to be treated differently.

A pH study is usually done at an endoscopy center and occasionally may be performed at a doctor’s office. It is generally done without sedation; a tiny probe is moved up the nose and down into the esophagus. The probe is connected to an event recorder, which looks like a pager. This recorder measures the amount of acid in the esophagus and how long it stays there. You go home with this and return the next day. When you experience pain or heartburn, you push a button on the event recorder and the time is noted. The whole device (probe and monitor) is worn for about 24 hours. When you return to the doctor’s office, the probe is easily removed and a computer analyzes the event recorder. This provides a lot of information such as how often in a 24-hour period your acid reflux occurs; how long it lasts when it does occur; and whether your subjective symptoms agree with the presence of acid reflux or not.


By Mortin - Copyright 2009
Last modification 31/12/2009

What is a pH study?- References