Lactose intolerance test

What is a lactose intolerance test?

A lactose intolerance test measures the ability of the intestines to break down a type of sugar, known as lactose, found in milk and other dairy products, when it is suspected that the substance is not well digested and causes discomfort.

What does it consist of?

There are two types of lactose intolerance tests: a blood test to detect the presence of blood glucose before and after having ingested a substance containing lactose, and the hydrogen breath test, before and after ingesting food containing lactose.

In the breath test, you must blow into a special container and fill it with air. The breath sample is then tested to see how much hydrogen is present. Before the test, you will not be able to eat or drink anything for several hours (you should not eat or drink the night before the test, or on the morning of the test). After the first sample is taken, you will be given a solution containing lactose and asked to drink it. Your breath is then measured every 15 minutes afterwards. Depending on the results obtained in each phase, the test can go on for several hours. Subsequently, the hydrogen of the bags or breath vessels will be analysed to obtain a detailed diagnosis.

Why is it done?

This test is done to find out if you have any signs of lactose intolerance.

Preparation for the lactose intolerance test

You should avoid eating any food or performing any physical exercise for eight hours before undergoing the test.

How does it feel during the exam?

This test does not cause any pain or discomfort. If a blood sample is taken, then the needle may prick a little, but it should not be painful.

Risks of the lactose intolerance test

This test does not carry any significant risk.