There are various ways of identifying lactose intolerance. The simplest method is a self-test: if you notice that you can no longer consume the same amounts of milk and dairy products as before without complaints, this is at the very least a sign of lactose intolerance. Professional lactose-intolerance tests provide a clear verdict.

Lactose intolerance: Best identified by your physician.

If you want to be tested for lactose intolerance, you should always consult your physician. Medical experts can identify intolerance on the basis of breath tests or blood tests.
In these tests, the physician gives the patient a certain amount of lactose and then checks either the blood levels or the breathing levels at regular intervals.

Lactose tolerance test with subsequent measuring of blood-sugar levels

As the body is either partially or totally unable to separate lactose into glucose and galactose in the event of lactase deficiency,
consumption by sufferers leads to only a slight increase in glucose levels in the blood or no increase at all. Consequently,
blood-sugar levels can be used to determine the existence of lactose intolerance.

Lactose tolerance test with subsequent measuring of exhaled air

If no separation takes place, lactose enters the large intestine, where bacteria break it down. This results in the formation of substances such as
hydrogen, which enters the lungs via the intestinal wall and the bloodstream and is ultimately exhaled.
So if the exhaled air has a raised water content after consumption of lactose, this indicates lactase deficiency.