Esophageal pH Test
Reviewed
An esophageal pH test measures how often and how long stomach acid enters the esophagus. It helps diagnose acid reflux or GERD and can check if treatment is working.
Preparation and collection
Do not eat or drink for 4 to 6 hours before the test. You may need to stop taking certain medicines (such as antacids) for 24 hours up to 2 weeks before the test. Tell your provider if you have a pacemaker, implantable heart defibrillator, previous esophagus problems, or a history of bleeding problems.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- Procedure may cause mild discomfort or rare complications such as nosebleed or esophageal tear.
- Results may be affected by recent use of acid-reducing medications or by eating patterns during the test.
What to do next
Based on your results, your provider may recommend lifestyle changes (eating smaller meals, avoiding trigger foods, not lying down after eating), quitting smoking, weight loss, over-the-counter or prescription medicines to reduce acid, or in severe cases, surgery.