24-hour pH measurement: everything you need to know about reflux testing

Do you often feel a burning sensation in your chest after eating? Do you wake up at night feeling suffocated? These symptoms may indicate reflux disease, which can be detected by accurate diagnostic methods. A 24-hour pH measurement is one of the most reliable tests that can help you find out if your symptoms are indeed caused by reflux and how severe your problem is.

In this article, we explain in detail what exactly 24-hour pH testing is, how it works, what to expect and how it can help you finally find the cause of your symptoms. Don't worry - the test is not painful and provides valuable information that your doctor can use to develop a personalised treatment plan.

What is 24-hour pH measurement?

24-hour pH monitoring (also known as ambulatory pH monitoring) is a diagnostic procedure that continuously measures the acidity in the oesophagus for a full day. The technique is designed to detect when and how often stomach acid is being returned to the oesophagus - i.e. when reflux occurs.

The test is particularly useful if:

You have regular heartburn, but the gastroscopy shows no abnormalities

Chest pain not explained by cardiology tests

Symptoms persist despite proton pump inhibitor (PPI) medications

Atypical symptoms such as cough, hoarseness or sore throat

Why is accurate measurement important?

Traditional tests, such as gastroscopy, only give a snapshot of the condition of the oesophagus. 24-hour pH measurement, on the other hand, tracks what's happening in your body in real time throughout the day - while you eat, rest or sleep. This allows you to:

They determine exactly how long your oesophagus is exposed to stomach acid

Linking symptoms to episodes of reflux

Distinguish between normal (physiological) and abnormal levels of reflux

How is the test done? Step by step

Preparations before the test

5-7 days before the test, your doctor may ask you to stop taking medicines that reduce stomach acid (PPIs, H2 blockers). This is important to get an accurate picture of your natural acid production. Do not worry if your symptoms increase during this time - this is to be expected and is only temporary.

What to do before the test:

Tell your doctor about any medicines you are taking

Ask which medicines you should stop taking

Eat normally the day before the test

Wear comfortable, loose clothing on the day of the test

Inserting the probe

The test is usually done in the morning. The doctor or specialist assistant inserts a thin, flexible probe through your nose into your oesophagus. The tip of the probe is positioned about 5 cm above the stomach lining (lower oesophageal sphincter).

What to expect:

Slight discomfort during insertion

Sensitivity to mucous membranes or nausea (rare)

Insertion usually takes 5-10 minutes

Local anaesthetic spray can help reduce discomfort

The probe is thin and flexible, so most people get used to it quickly. Although you may feel its presence, especially when swallowing, it does not interfere with normal activities.

24-hour monitoring

The probe is attached to a small attachment that you can hang on your belt or around your neck. This device continuously records pH values and stores the data.

Important rules during the 24 hours:

Continue your normal daily routine

Eat and drink as you are used to (unless your doctor recommends otherwise)

Avoid extreme physical exertion

Do not bathe or shower (the device is not waterproof)

Keep a diary of your meals, symptoms and activities

Using the event indicator

There is a button on the recorder that you should press when you notice a symptom (e.g. heartburn, chest pain, cough). This allows the doctor to link your complaints to the pH values measured.

When to press the button:

When heartburn occurs

For chest pain

When regurgitation (backflow of food) is detected

When coughing, hoarseness or other respiratory symptoms occur

Keeping the diary

It is essential that you keep an accurate log for 24 hours. Make a note of:

Meal times and contents

Type and amount of fluids drunk

Time and nature of symptoms

Lying/standing position

Start and end of sleep

This diary will help your doctor understand which activities or foods trigger reflux.

Removing the probe

After 24 hours, you will return to the surgery to have the probe removed. This is a quick and painless process that takes only a few seconds.

An alternative to wireless pH monitoring

Some healthcare facilities also offer wireless pH monitoring. In this case, a small capsule-sized sensor is attached to the esophageal mucosa during gastroscopy. This device sends data to a receiver attached to your body for 48-96 hours, and then detaches and is emptied through the intestinal tract.

Advantages of the wireless method:

No probe through the nose

More comfortable in everyday activities

Longer monitoring period possible

Shower and bath

Disadvantages:

It can be more expensive

Less invasive (requires gastroscopy)

May rarely cause chest discomfort until sensor detachment

What do the results show?

After the test, your doctor will analyse the data and determine whether your reflux is normal or abnormal.

Key indicators

1. Savexposition time

The most important indicator is the amount of time spent in the oesophagus at a pH below 4 (acidic). The normal values are:

Stationary position: less than 10.5% of time

In the lying position: less than 6% of time

Total in 24 hours: less than 4-5% of time

If these values are higher, it indicates an abnormal level of reflux.

2. Number of reflux episodes

The test shows how many times reflux has occurred in the 24 hours. More than 50 episodes of reflux are usually considered abnormal.

3. Longest reflux episode

Measures how long the longest acid episode lasted. If it is more than 20 minutes, this could be worrying.

4. DeMeester score

It is a composite score that takes into account several factors. A score above 14.72 indicates pathological reflux.

Symptom-reflux relationship

The doctor will check whether the symptoms reported coincide with the measured episodes of reflux. This will help determine:

Reflux disease (GERD): If there is abnormal savex exposure and symptoms are associated with reflux events.

Reflux hypersensitivity: If the savexposure is normal but the symptoms are still associated with episodes of reflux. In this case the oesophagus is hypersensitive to normal amounts of acid.

Functional heartburn: If the savex position is normal and the symptoms are not related to reflux events. Then a different treatment approach is needed.

What diseases can be diagnosed?

24-hour pH measurement helps to detect several conditions:

Gastroesophageal reflux disease (GERD)

This is the most common indication. The test confirms whether the symptoms are indeed caused by abnormal acid reflux and helps to determine the intensity of treatment.

Atypical reflux symptoms

Sometimes reflux does not present as traditional heartburn but as:

Chronic cough

Worsening of asthma

Reluctance, change of voice

Sore throat, difficulty swallowing

Tooth enamel damage

A pH measurement will help to find out if these complaints are related to reflux.

Non-heart-related chest pain

If cardiological tests have ruled out heart disease but you still have chest pain, pH monitoring can help determine whether the pain is coming from the oesophagus.

Evaluating the effectiveness of PPI therapy

If you are taking medicines that inhibit stomach acid but your symptoms persist, the test may show:

Still have abnormal levels of reflux (medicine not effective enough)

No reflux, but symptoms still occur (other cause)

Frequently asked questions about the study

Is the test painful?

Inserting the probe can be uncomfortable, but not painful. Most people feel mild pressure or nausea for a few seconds. You may also feel the presence of the probe for up to 24 hours, but this is not pain, more of an embarrassing sensation.

Can I eat and drink during the test?

Yes, in fact, it is very important! The doctor wants to see what happens under normal circumstances, so eat and drink as you are used to. But avoid extremely acidic or fatty foods if you don't eat them regularly anyway.

What if I need to vomit?

It is rare, but if you feel nauseous, try to breathe deeply and sip water slowly. If you do vomit, contact your doctor's office immediately, as the probe may be dislodged.

Does it work while you sleep?

Yes, the investigation is ongoing. In fact, data at night are particularly important, as many people have worsening reflux when lying down.

How much does the test cost?

Costs vary from health institution to health institution. In Hungary, social insurance will cover all or part of the examination if the doctor deems it justified. It is worth asking in advance about the exact costs and the social security contributions.

Are there side effects?

Most people tolerate the test well. Side effects are rare:

Nosebleeds (very rare)

Mild sore throat

Nervousness or anxiety about the presence of the probe

Temporary nausea

These are usually mild and go away quickly after the probe is removed.

What to do after the test?

Evaluation of results

Results are usually ready within 1-2 weeks. Your doctor will review the data and discuss the next steps with you in detail:

The extent and frequency of reflux

Association between symptoms and reflux

Diagnosis and recommended treatment

Treatment options

Based on the results of the test, your doctor may recommend several treatment options:

Lifestyle changes:

Weight loss (if necessary)

Stopping smoking

Reducing alcohol consumption

Raising the head end of the bed

Eating smaller portions

Avoiding foods that trigger reflux

Medication:

Proton pump inhibitors (PPIs) at higher doses

H2-receptor blockers

Prokinetics (medicines to help with gastric emptying)

Preparations containing alginic acid

Surgical intervention:
If medication is not effective and you have severe reflux disease, fundoplication (reflux surgery) may be considered. This is a minimally invasive procedure to strengthen the stomach lining.

Summary: Why should you have the test done?

24-hour pH measurement is the gold standard method for reflux diagnosis. Although the probe may be uncomfortable to wear, the information obtained is invaluable for making an accurate diagnosis and determining the appropriate treatment.

If you have been taking stomach acid suppressants for months without results or have unresolved chest pain, this test may finally answer your questions. Don't let fear or uncertainty hold you back - talk to your doctor about whether 24-hour pH testing is right for you.

Where can the tests be carried out?

Several gastroenterology centres and hospitals in Hungary perform 24-hour pH monitoring. Your family doctor or specialist will be able to recommend a suitable facility and help you with a referral.

Remember: the more accurate the diagnosis, the more effective the treatment. 24-hour pH monitoring can help you finally find the real cause of your symptoms and regain your quality of life.