Esophageal pH Study

A 24-hour esophageal pH study is used to measure the number of acid reflux episodes a patient experiences during a 24-hour period. The study also measures the amount of time (in minutes) that stomach acid is present in the patient’s esophagus and allows for evaluation of the patient’s symptoms with activity, at home or work, and especially during sleep.

The information obtained from this study will show if acid reflux is causing non-cardiac chest pain, hoarseness, coughing, halitosis or asthma, and will also measure normal acid levels. From this study, your physician will plan treatment for your particular health problem.

The Procedure

The 24-hour esophageal pH study takes place in an examination room. You will not be asked to remove any clothing, and sedation is not usually given. Your appointment will last about one hour, including outpatient admission, instruction and placement of the pH catheter.

  • The nurse will spray the inside of your throat with a topical anesthetic and will use an anesthetic lubricant on the small, flexible pH tube
  • The tube (1/8 inch in diameter) is gently placed into one nostril and guided into the esophagus
  • The end of the tube is positioned precisely 2 inches above the diaphragm, where acid sensing occurs
  • After the pH catheter is placed, it is secured to the end of your nose and side of your face with small pieces of silk tape
  • The catheter is attached to a “Walkman” type recorder, which is provided

After Your Appointment

After your appointment you will be able to resume normal activities. Some patients find that the pH catheter does not interfere with their normal activities, while others find it to be annoying and choose to have someone drive them home. You will need to return to Digestive Health Specialists 24 hours after the procedure to have the catheter removed. Removal will only take about 5 minutes.

The catheter may cause:

  • Watery eyes
  • Runny nose
  • Sore throat


24-hour pH esophageal monitoring is a very low risk procedure, when performed by competent specialists. Complications such as perforations (tearing) or bleeding of the gastrointestinal wall can occur, but they are rare. Equipment failure or death are extremely unlikely but remain remote possibilities.

Please feel free to contact us with any questions or concerns, either before or after your appointment.