If your doctor thinks you have lactose intolerance based on your symptoms, your doctor can request a test. There are a few different tests.
Hydrogen breath test:
This is a simple way of making sure you’re lactose intolerant or not.
The night before the test you can’t drink or eat anything. And in the morning the same, no drinks or food allowed. The first thing what you’ve to do is breath in a machine. They test your breath how it is ‘normal’. Then you’ll have to drink a lactose solution and your breath will be tested every 30 minutes for 3 hours. If the hydrogen levels are high in your breath, it’s likely you’re lactose intolerant.
Lactose tolerance test:
This is similar to the hydrogen test. You can’t eat or drink anything the night and morning before the test. You will get a lactose solution drink as well. Only now they are gonna test your blood. They will take a blood sample and test how much glucose (blood sugar) it contains. If your blood sugar level is low, then it’s most likely you’re lactose intolerant. This is because your body doesn’t brake down the lactose into glucose.
Milk tolerance test:
This is one is similar to the lactose tolerance test, because they will test your blood sugar level as well. Only this time after drinking a glass of milk.
The most common test is the hydrogen test, because this one is really easy to take and very accurate! You only have to wait about a week for the results, but most of the time you will notice yourself. Because if you can’t tolerate lactose too well, you will have severe symptoms after drinking a lactose solution.