What is analysed in a test for lactose tolerance?

The tests evaluate the intestines’ ability to break down lactose.

How are these tests used?

There are two types of lactose tolerance tests. A hydrogen breath test measures the amount of hydrogen gas in the breath before and after drinking a liquid containing lactose. This is the most common test. Then there is a blood glucose test, which involves blood analysis to measure glucose levels before and after ingesting a lactose-containing liquid.

Why is this analysis done?

To diagnose lactose intolerance, to evaluate symptoms such as diarrhoea, abdominal pain, bloating, gas, and nausea.

When should I be tested?

Ideally, as soon as symptoms appear after consuming dairy products. In high-risk situations or suspected intolerance.

What sample is required?

Samples are taken from the breath for the hydrogen test, and from the blood for the glucose test.

Is any prior preparation necessary?

Yes, you should fast (not eat or drink) for eight to 12 hours before the test. Discontinue antibiotics two to four weeks before. Avoid smoking or intense exercise the day before.

What are the normal values?

Negative: No evidence of lactose intolerance.

What does altered value indicate?

Positive: Indicates lactose intolerance.