How often it entersHow long it staysHow well it’s cleared out
Your healthcare provider may order this test to confirm a diagnosis or to periodically monitor your reflux symptoms and treatments.
This article explains why you may need the test and the ways the test is conducted. It also explains what you can expect to learn from the test results.
Purpose of Test
The pH test for acid reflux measures the amount of acid backing up into the esophagus. Performed with a thin, plastic tube armed with a sensor, this procedure is often done when:
You have GERD symptoms, but an endoscopy exam doesn’t detect any evidence of reflux disease The standard treatment of a twice-daily dose of proton pump inhibitor (PPI) medication doesn’t help Less common symptoms of GERD (such as chest pain, nocturnal cough, asthma, hoarseness) need to be evaluated
Before testing, your healthcare provider will ask you about your symptoms of GERD. These include:
HeartburnNausea or abdominal painDifficulty swallowingChronic cough
Your healthcare provider will also ask you about your risk factors for GERD, including whether you have a hiatal hernia, smoke, take medications, or eat foods that could predispose you to reflux.
Before Your Test
You will be instructed not to eat after midnight before your procedure. Because some medications can affect the test results, you may be told to avoid taking some prescription or over-the-counter medications. Discuss this with your healthcare provider.
If the diagnosis is uncertain or your symptoms are chronic, and there are concerns about complications, further testing is recommended. The standard test is an upper endoscopy in which a tube is passed through your mouth and into your esophagus and stomach.
Sometimes this test shows no evidence of abnormality to explain your symptoms. That’s when your healthcare provider may recommend pH monitoring.
Medications that are sometimes paused include:
Adrenergic blockers Antacids Anticholinergics Cholinergics Corticosteroids H2 blockers (such as famotidine) Proton pump inhibitors
During the Test
To conduct a pH test, your healthcare provider must place a monitor into your esophagus to track acid levels. There are two types of monitors that are used for this test: a catheter and a wireless capsule.
Catheter Test
The catheter is placed using a scope. Your healthcare provider will usually place an IV and give you medication to relax you. They may also spray the back of your throat with medication.
A tube with a sensor on its end is inserted through your mouth or nose and into your esophagus. The sensor is then attached to the lining of the esophagus, and the tube is removed. the sensor will wirelessly send data to a monitor that you can wear around your waist or shoulder.
Capsule Test
For this procedure, you will need to swallow a disposable capsule—about the size of a large pill. This will travel down through your esophagus, stomach, and intestine. It wirelessly records data about your symptoms and when you eat or lie down.
Both types of sensors will gather information about your symptoms. You are encouraged to engage in everyday activities and keep a diary of what you eat and any GERD episodes or suspected acid reflux issues and symptoms, such as coughing and wheezing. This can help your healthcare provider determine if acid reflux is related to unexplained asthma or other respiratory symptoms.
After the Test
After your monitor is placed or swallowed, your throat may feel slightly sore for a day. Sucking on lozenges or hard candy may help soothe this discomfort. The sensor itself should not cause any pain or be detectable. It will pass through your digestive tract within days and be excreted without problems.
Your healthcare provider will review the data gathered by the sensor and your diary entries. You will need to schedule a follow-up appointment to review these results.
Interpreting Results
Typically, the pH level in the esophagus should be close to 7.0. Esophageal pH tests look for intervals in which pH reaches lower levels, such as below 4.0, which is highly acidic and means that you’re experiencing a surge of stomach acid.
While abnormal results may indicate GERD, increased stomach acid may also be due to conditions such as:
Barrett’s esophagus Dysphagia Esophageal scarring Esophagitis
If your pH monitoring results reveal that your pH is normal, but you’re still experiencing GERD symptoms, another type of testing may be recommended. These tests may include a barium swallow or an upper endoscopy (esophagogastroduodenoscopy).
Depending on your results, your healthcare provider may recommend lifestyle changes and medications to ease your symptoms and prevent complications.
Summary
The esophageal pH test checks how much stomach acid enters your esophagus and how long it remains. It’s an important test to diagnose or monitor GERD. It can be used to help you manage your symptoms or to identify other possible health conditions that could be causing GERD-like problems.
A Word From Verywell
Chest pain and symptoms such as coughing or wheezing are often signs of GERD, but they can also be related to other conditions. To ensure you have the right diagnosis and to find clues to how you can best manage your symptoms if they are related to GERD, an esophageal pH test is worth it. It can be a bit uncomfortable and inconvenient for a day, but the information gathered can help you enjoy a better quality of life and peace of mind.
