What tests are used to diagnose gastroesophageal reflux disease (GERD)?

Your doctor may use endoscopy to diagnose your GERD. This procedure allows your physician to directly visualize the esophageal lining (mucosa). The degree and extent of reflux can be further investigated with a barium x-ray study of the esophagus. This also gives information about the function of the swallowing mechanism. There are some other tests your doctor may recommend for diagnosing GERD.

It may require no more than visiting your doctor and answering a few questions about your symptoms to determine if you have heartburn from acid reflux. Your doctor can then recommend several different treatment options, depending on your particular symptoms and medical profile.

Additional diagnostic tools:

  • Upper gastrointestinal barium study: Also called an upper GI series, this test allows for examination of the upper parts of the gastrointestinal tract, including the esophagus, stomach and small intestine.
  • Upper endoscopy: For this test, the doctor uses a flexible tube equipped with a lens, called an endoscope, to view your esophagus, your stomach and the upper part of your small intestine (duodenum). Suspicious areas can be biopsied during—the exam.
  • Esophageal manometry: This test uses soft tubing, inserted through the nose, or sometimes the mouth, to measure the pressure in the esophagus and the lower esophageal sphincter (LES).
  • Esophageal pH monitoring: This test uses a probe to monitor and record acid levels near the LES. The probe is inserted via the nose.

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Symptoms of gastroesophogeal reflux disease (GERD) include heartburn.

The following are tests used to diagnose heartburn and gastroesophageal reflux disease (GERD):


  • Typically takes place in a hospital or outpatient facility
  • Involves placing a flexible tube with a light and camera through your mouth to look at the esophagus and stomach. 
  • During the procedure you will be sedated with medication given through an IV. 
  • Tissue samples can also be taken of any suspicious area that may be seen. 

Bravo Capsule pH Monitoring Procedure 

  • Patient-friendly test for identifying the presence and severity of acid reflux. 
  • A capsule is attached to the lining of the esophagus during an endoscopy, allowing detailed information about the nature and extent of your heartburn to be collected over multiple days. 
  • Your doctor then evaluates reflux symptoms by determining the frequency and duration of acid flowing back up into the esophagus. 
  • Maintenance of regular activities and a normal diet during the test has the potential to provide a more accurate picture of acid exposure, compared to data collected using catheter-based systems where normal activities may be limited. 

Esophageal Manometry 

  • Tests the muscular activity of your esophagus.
  • Tells you if the contractions of your esophagus are well-coordinated and functioning properly to clear it of food and acid. 
  • Can detect if the contractions are spasmodic and non-propulsive in nature which can cause atypical chest pain and GERD-like symptoms.
  • Measures the strength of the lower esophageal sphincter (LES). 

With GERD, the problem is often that the valve (LES) responsible for keeping the acid in the stomach is consistently, or at times, too weak to do its job. If valve strength is below 6mm Hg, medication probably won't treat you appropriately. In this case surgery may be a good option and manometry can tell you which of several operative options is best for you. 

It is common for your physician to start you on medication as a trial without performing these tests. That is fine if it is only for a short period of time to evaluate your response. However, whether that empiric trial addresses the problem or not, I believe that your physician should consider these evaluations very early to establish your GERD identity. This can only be done if he or she “knows your numbers” and those numbers can be determined by these tests. It is always best to start a treatment based on an accurate diagnosis.

GERD is initially diagnosed by symptoms and a patient's response to a class of drugs called proton pump inhibitors which reduce the stomach's production of acid.

Doctors diagnose complicated GERD with endoscopy. Our gastrointestinal specialists may also conduct a test, called esophagogastroduodenoscopy (EGD), in which a thin, flexible tube with a light and camera—an endoscope—is inserted into the throat to visualize the esophagus and stomach to determine if there is inflammation or an ulcer. A tissue sample can be taken to test for Barrett's esophagus, a precancerous condition in which cells in the esophagus become abnormal.

A barium swallow x-ray may also be performed to determine if structural abnormalities such as a hiatal hernia, an ulcer or narrowing of the esophagus exist. Patients are given a liquid solution to drink, and x-rays are then taken to visualize the esophagus.

Another test may be performed, called a Bravo pH test, which uses a tiny acid-measuring probe to determine when and for how long reflux occurs. While sitting, a patient's throat is numbed with a spray, and using an endoscope, the physician inserts a tiny probe into the throat and attaches it to the lower area of the esophagus. The probe transmits a signal to a small computer worn around the waist for two days, after which the probe is excreted through the stool.

Gastroesophageal reflux disease (GERD) can often be diagnosed clinically based on patient history. Often, no further work-up needs to be done prior to treatment. If the diagnosis is in question or the reflux is significant, there are tests that can be done. These tests include:

  • Esophageal manometry, which tests the function of the esophagus
  • Upper GI series, in which the patient swallows a contrast media while viewed by X-ray
  • EGD (esophagogastroduodenoscopy), in which the doctor uses a scope to look down the esophagus into the stomach


First and foremost, your doctor will consider your symptoms when diagnosing gastroesophageal reflux disease (GERD) and heartburn. If you suffer from heartburn frequently, your doctor will probably want to conduct some tests to determine whether you have GERD, which is more serious than occasional heartburn, or might refer you to a gastroenterologist (a digestive system specialist) for further tests. These tests might include taking X-rays of your digestive system, examining your esophagus using a thin tube called an endoscope, or measuring the amount of stomach acid in your esophagus over a specific period of time, such as 24 hours. Your doctor or the gastroenterologist might also conduct a biopsy, taking a small sample of tissue from your esophagus and sending it to a lab for further tests.

When a patient experiences common symptoms of gastroesophageal reflux disease (GERD), namely heartburn and/or acid regurgitation, additional tests prior to starting treatment are typically unnecessary. If symptoms do not respond to treatment, or if other symptoms such as weight loss, trouble swallowing or internal bleeding are present, additional testing may be necessary.

Upper endoscopy is a test in which a small tube with a light at the end is used to examine the esophagus, stomach and duodenum (the first portion of the small intestine). Before this test, you will receive medications to help you relax and lessen any discomfort you may feel. An upper endoscopy allows your doctor to see the lining of the esophagus and detect any evidence of damage due to GERD. A biopsy of tissue may be done using an instrument similar to tweezers. Obtaining a biopsy does not cause pain or discomfort.

Another test, known as pH testing, measures acid in the esophagus and can be done by either attaching a small sensor into the esophagus at the time of endoscopy or by placing a thin, flexible probe into the esophagus that will stay there for 24 hours while acid content is being measured. This information is transmitted to a small recorder that you wear on your belt. X-ray testing has no role in the initial evaluation of individuals with symptoms of reflux disease.

Dr. Roshini C. Rajapaksa, MD

GERD, or gastroesophageal reflux disease, can be diagnosed just based on symptoms alone, but can also be diagnosed using medication or via tests with your doctor. Watch gastroenterologist Roshini Raj, MD, discuss how GERD is commonly diagnosed.

Dr. Gary W. Falk, MD

Ambulatory pH testing is currently the best method to diagnose gastroesophageal reflux disease (GERD). These tests are used to demonstrate abnormal esophageal acid exposure as well as the correlation between episodes of acid exposure and symptoms. Traditional pHmetry involves passage of a transnasal catheter connected to an external monitoring device that records the pH in the esophagus and stomach over a 24-hour period. Today, pHmetry can be accomplished with improved catheter-based tests that also measure impedance or with catheterless (wireless) tests that are more comfortable.

Dr. Lawrence S. Friedman, MD

Many people can manage heartburn without seeking medical care through dietary changes, over-the-counter medications, and relaxation therapy. A doctor can be helpful if your gastroesophageal reflux disease (GERD) symptoms don't respond to self-help techniques and they interfere with sleep or daily life. If you do seek your physician's advice, providing a detailed account of your symptoms will help him or her make the diagnosis.

The doctor will review your medical history and ask detailed questions about the nature of the pain and its pattern of onset. For example, he or she might ask whether symptoms are worse after you eat a heavy meal or known dietary troublemakers such as high-fat foods or dairy products. Your doctor will want to know if bending over to tie your shoelaces or lying down aggravates the symptoms, and whether the pain seems linked to anxiety or stress.

For typical reflux symptoms, doctors usually forgo diagnostic tests and proceed straight to treatment, starting with a proton pump inhibitor (PPI) such as omeprazole or lansoprazole. If these acid-suppressing medications provide relief, the odds are that the diagnosis of GERD was correct. Once symptoms are under control, the patient may either continue with the PPI or switch to a less powerful medication. That might be an H2-receptor antagonist (H2 blocker) such as cimetidine (Tagamet), ranitidine (Zantac), or famotidine (Pepcid), or an antacid like Tums. If the medicine doesn't relieve your symptoms or if other symptoms need investigation, the doctor might use diagnostic tests to detect reflux, measure pH levels in the esophagus, or rule out other conditions.

Different medical tests are use to diagnose acid reflux, GERD or Barrett's Esophagus. In this video, Sharmila Anandasabapathy, MD, a gastroenterologist at The Mount Sinai Medical Center, discusses the procedures used to diagnose each condition.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.