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Heartburn/GERD Health Center

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Esophageal pH Test for Heartburn and Acid Reflux

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The esophageal pH test is an outpatient procedure performed to measure the pH or amount of acid that flows into the esophagus from the stomach during a 24-hour period.

The procedure is commonly used to help confirm the diagnosis of GERD or to identify the cause of various symptoms, including:

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  • Heartburn, primarily in patients who have had a normal endoscopy and who have failed medical treatment and may be considered as candidates for surgery
  • Uncommon symptoms of GERD (gastroesophageal reflux disease), such as chest pain, chronic cough, asthma, and other throat symptoms

The test may also be performed to evaluate the effectiveness of current treatments for heartburn or reflux. This test is often recommended for those whose symptoms aren't helped by medications.

How Is the Esophageal pH Test Performed?

The equipment used in the esophageal pH test consists of a small probe that is inserted through your nostril and positioned near the lower esophagus. The probe is plugged into a small unit (or monitor) worn on your belt or over your shoulder. A newer, wireless device may make monitoring the pH level easier: Instead of having to have a tube placed down your nose for 24 hours, your doctor will place a disposable capsule into the esophagus using an endoscope. The capsule then wirelessly transmits information to a receiver worn around the waist.

With the touch of a button on your monitor, it will record the following information:

  • The occurrence of symptoms
  • The times when you eat and lie down

A nurse will review the monitoring instructions with you.

Be careful with the monitor and keep it dry at all times.

What Happens Before the Esophageal pH Test?

Do not eat or drink for four to six hours before your esophageal pH test.

Tell your doctor if you are pregnant, have a lung or heart condition or any other diseases, or are allergic to any medications.

Can I Continue to Take Medication Before the Esophageal pH Test?

There are several medications that may affect the results of an esophageal pH test. These include:

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