An esophageal 24-hour pH test measures and records the pH in your esophagus during the testing period. This test is performed to diagnose gastroesophageal reflux disease (GERD). GERD is a condition where the acid of the stomach refluxes or reenters the esophagus through the lower esophageal sphincter (LES). The test may also be used to determine if a patient’s medications are effective.


It is important to follow your doctor’s specific instructions prior to the scheduled exam. If the test is being used to diagnose GERD, you will be asked to cease taking any prescription or over the counter heartburn medicine. If this test is being used to determine a medication’s effectiveness in treating GERD, you will continue your normal medication routine as directed. Your doctor’s instructions will be complete for your individual needs.

The Test

A small, thin tube with a pH sensitive tip is inserted into the esophagus through the nose and attached approximately 2 inches from the LES. The tube is gently secured to the side of the patient's face and the other end is attached to a recorder that is worn on the patient’s belt or shoulder. Over the next 24 hours, the patient goes about their normal activity. It is important to eat some foods that are heartburn triggers so the test can detect your symptoms. When a symptom arises, the patient presses a button on the recorder. Pressing this button records the event.

After 24 hours is over, the patient returns to the office where the tube removed and the information on the recorder is downloaded for analysis. A follow-up appointment is necessary to discuss the results of the test and a next steps for treating your symptoms.

Before your visit, please view the patient forms available online.

24-Hour pH Probe Procedure and General Patient Forms