If you have the typical symptoms of lactose intolerance, the next step is to find out whether you really are lactose intolerant.
Diagnosis of lactose intolerance: what tests does the doctor do? The H2 breath test:
There are various methods for diagnosing lactose intolerance. The most reliable method to determine this intolerance is the hydrogen breath test (H2 breath test).
In this method, the patient: takes a test solution consisting of 25 g of lactose dissolved in warm water on an empty stomach.
The patient then: blows into a breath test device at certain intervals, which measures the hydrogen content in the breath.
In people whose bodies cannot properly metabolize the ingested lactose, intestinal bacteria produce hydrogen. This hydrogen then enters the bloodstream and can be measured in the breath.
The doctor treating the patient can determine the presence of lactose intolerance based on the hydrogen levels measured.
How long does an H2 breath test take?
The diagnosis with this method takes between two and three hours. In addition to the hydrogen breath test, there are other methods for diagnosing lactose intolerance.
Alternative tests
Other methods of diagnosis include measuring blood glucose levels, a genetic test or a small intestine biopsy. However, these methods are less accurate and are only carried out in certain circumstances.
Lactose intolerance test: also possible at the drugstore or pharmacy?
Since the coronavirus pandemic at the latest, medical self-tests that you can buy at the drugstore or pharmacy and carry out from the comfort of your own home are nothing new. Similar tests are also available for numerous other ailments. For example, self-tests can also be used to check vitamin intake, possible nutrient deficiencies or allergies and intolerances.
However, these tests are generally not quite as simple as the Corona rapid test. Although users can carry out the test anywhere and at any time and are therefore independent of waiting times and lengthy appointments with the doctor, they do not receive the result immediately. Instead, the samples have to be sent in and analyzed by specialist laboratories.
Similar to a doctor's appointment, the hydrogen content of the exhaled air is usually measured over several hours. To do this, a reference breath sample is first taken on an empty stomach. Then a defined amount of cow's milk is drunk and blown into the breath sample tube again. After completion of the test, the breath samples are placed in the enclosed return envelope and sent to a medical laboratory for analysis.
References
- Di Costanzo M, Berni Canani R - Lactose Intolerance: Common Misunderstandings, Ann Nutr Metab. (2018)
- Cerascreen - Selbsttest
- Rathaus Apotheke - Laktoseintoleranz, was nun? (2023)