Esophageal pH Test
Reviewed
Also called: esophageal pH monitoring, 24-hour esophageal pH test, esophageal reflux monitoring, esophageal acidity test, pH monitoring, pH probe study
An esophageal pH test measures how often and how long stomach acid enters the esophagus. It helps diagnose acid reflux or GERD and can check if treatment is working.
Specimen: Not applicable (esophageal pH measurement via catheter or wireless probe)
Why this test may be ordered
- To diagnose acid reflux or GERD
- To see if treatment for GERD is effective
Preparation and collection
Do not eat or drink for 4 to 6 hours before the test. You may need to stop taking certain medicines (such as antacids) for 24 hours up to 2 weeks before the test. Tell your provider if you have a pacemaker, implantable heart defibrillator, previous esophagus problems, or a history of bleeding problems.
A thin catheter is inserted through your nose or mouth into the esophagus and connected to a monitor worn for 24 hours. Alternatively, a wireless pH probe is placed in the esophagus during an upper endoscopy, where it monitors acid for 48 to 96 hours.
During a catheter test: mild discomfort in the nose and throat, possible gagging, rarely a nosebleed. During a wireless test: sore throat from the endoscope; very rarely, a tear in the lining of the esophagus.
Understanding results
Results show the acid level (pH) in your esophagus over the monitoring period. High acid levels may indicate acid reflux or GERD. Normal levels suggest no significant acid reflux was detected during the test.
- High acid levels: May indicate acid reflux, GERD, esophagitis, esophageal stricture, or Barrett's esophagus. Limitation: These findings do not diagnose a specific condition; further evaluation is needed. Next step: Consult your healthcare provider for additional testing and to discuss management options.
- Normal acid levels: No significant acid reflux was detected during the monitoring period. Limitation: Intermittent reflux may not be captured; symptoms could still be caused by other conditions. Next step: If symptoms persist, talk to your provider about other possible causes or repeat testing.
- Procedure may cause mild discomfort or rare complications such as nosebleed or esophageal tear.
- Results may be affected by recent use of acid-reducing medications or by eating patterns during the test.
What to do next
Based on your results, your provider may recommend lifestyle changes (eating smaller meals, avoiding trigger foods, not lying down after eating), quitting smoking, weight loss, over-the-counter or prescription medicines to reduce acid, or in severe cases, surgery.
- How should I prepare for the esophageal pH test?
- What are the risks of the catheter and wireless probe methods?
- What do my results mean for my treatment plan?
- Can I eat normally during the monitoring period?
- When will I get my results and discuss next steps?