Esophageal pH Monitoring – Indications, Procedures, Results

Last updated: February 8, 2026 Medically reviewed by: RxHarun Orthopedic Specialist Doctor Reading time: 2 min read

pH monitoring – esophageal; Esophageal acidity test

Esophageal pH monitoring is a test that measures how often stomach acid enters the tube that leads from the mouth to the stomach (called the esophagus). The test also measures how long the acid stays there.

How the Test is Performed

A thin tube is passed through your nose or mouth to your stomach. The tube is then is pulled back into your esophagus. A monitor attached to the tube measures the acid level in your esophagus.

You will wear the monitor on a strap and record your symptoms and activity over the next 24 hours in a diary. You will return to the hospital the next day and the tube will be removed. The information from the monitor will be compared with your diary notes.

Infants and children may need to stay in the hospital for the esophageal pH monitoring.

This test can also be done during upper GI endoscopy by clipping a pH monitor to the lining of the esophagus.

How to Prepare for the Test

Your health care provider will ask you to not eat or drink after midnight before the test. You should also avoid smoking.

Some medicines may change the test results. Your provider may ask you to not take these for between 24 hours and 2 weeks (or more) before the test. You also may be told to avoid alcohol. Medicines that you may need to stop include:

Adrenergic blockers
Antacids
Anticholinergics
Cholinergics
Corticosteroids
H2 blockers
Proton pump inhibitors

DO NOT stop taking any medicine unless told to do so by your provider.

How the Test will Feel

You briefly feel like gagging as the tube is passed through your throat.

Why the Test is Performed

Esophageal pH monitoring is used to check how much stomach acid is entering the esophagus. It also checks how well the acid is cleared downward into the stomach. It is a test for gastroesophageal reflux disease ( GERD ).

In infants, this test is also used to check for GERD and other problems related to excessive crying.

Normal Results

Normal value ranges may vary depending on the lab doing the test. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Increased acid in the esophagus may be related to:

Barrett’s esophagus
Difficulty swallowing (dysphagia)
Esophageal scarring
Gastroesophageal reflux disease (GERD)
Heartburn
Reflux esophagitis

You may need to have the following tests if your doctor suspects esophagitis :

Barium swallow
Esophagogastroduodenoscopy (also called upper GI endoscopy)

Risks

Rarely, the following may occur:

Arrhythmias during insertion of the tube
Breathing in of vomit if the catheter causes vomiting

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

Add references, clinical guidelines, textbooks, journal articles, or trusted medical sources here. You can edit this area later with a custom field named _rx_references.

Written by Dr. Harun Ar Rashid, MD - Arthritis, Bones, Joints Pain, Trauma, and Internal Medicine Specialist

Dr. Md. Harun Ar Rashid, MPH, MD, PhD, is a highly respected medical specialist celebrated for his exceptional clinical expertise and unwavering commitment to patient care. With advanced qualifications including MPH, MD, and PhD, he integrates cutting-edge research with a compassionate approach to medicine, ensuring that every patient receives personalized and effective treatment. His extensive training and hands-on experience enable him to diagnose complex conditions accurately and develop innovative treatment strategies tailored to individual needs. In addition to his clinical practice, Dr. Harun Ar Rashid is dedicated to medical education and research, writing and inventory creative thinking, innovative idea, critical care managementing make in his community to outreach, often participating in initiatives that promote health awareness and advance medical knowledge. His career is a testament to the high standards represented by his credentials, and he continues to contribute significantly to his field, driving improvements in both patient outcomes and healthcare practices. Born and educated in Bangladesh, Dr. Rashid earned his BPT from the University of Dhaka before pursuing postgraduate training internationally. He completed his MD in Internal Medicine at King’s College London, where he developed a special interest in inflammatory arthritis and metabolic bone disease. He then undertook a PhD in Orthopedic Science at the University of Oxford, conducting pioneering research on cytokine signaling pathways in rheumatoid arthritis. Following his doctoral studies, Dr. Rashid returned to clinical work with a fellowship in interventional pain management at the Rx University School of Medicine, refining his skills in image-guided joint injections and minimally invasive pain-relief techniques.