An esophageal pH test is an examination, that directly determines the regular reflux of acidic gastric contents into the esophagus, by measuring the acidity level. This measurement takes place during 24 hours.


With this examination, the doctor can determine whether a person suffers from acid reflux.


The esophagus is a hollow, muscular tube that runs down from the mouth to the stomach. At the lower end of the esophagus is a little muscle, the sphincter, which prevents the acidic gastric contents to pass into the esophagus. If this sphincter is not functioning properly, it leads to acid reflux.
The examination is conducted with a thin tube (catheter). At the end of the tube is a measurement point that measures the level of acidity. This measurement point is connected to a box that records the measured data.


The doctor moves the catheter through the nose into the esophagus and places the measurement point approximately five centimeters above the stomach entrance. The insertion can be nasty and often causes nausea. Drinking sips of water can facilitate the insertion. If the tube is in place, the patient feels nothing anymore. The tube is stuck with a patch to the nose and connected to the portable recording box (recorder). Next, the patient can go home and eat and drink anything.
The acidity in the esophagus is measured for 24 hours. During these 24 hours, the patient should keep a journal, in which is written down exactly what he or she eats and drinks and when there are symptoms.
The next day, the patient comes back and the doctor or nurse removes the tube. The doctor will then work out the measurements and checks whether the acidity level changes at the moment the patient has symptoms and after meals. The doctor subsequently discusses the results with the patient.