Lactose Tolerance Tests

What is a Lactose Tolerance Test?

A lactose tolerance test is a type of diagnostic test used to measure how well a person can tolerate the sugar lactose, which is found in dairy products. The test is used to diagnose lactose intolerance, a condition in which the body has a difficult time digesting lactose.

Preparation for the Test

Before having the lactose tolerance test, you should discuss any medications you are taking with your doctor, as they may influence the results. Your doctor may recommend avoiding certain certain medications before the test. You should also fast for at least eight hours before the test.

Procedure

During the test, a healthcare professional will take a blood sample and measure your blood sugar level. You will then be given a liquid containing lactose and your blood sugar will be measured again after two hours. The healthcare professional will compare your before-and-after blood sugar levels and use that information to diagnose lactose intolerance.

Types of Lactose Tolerance Tests

There are two types of lactose tolerance tests available: the glucose hydrogen breath test and the direct lactose tolerance test. During the glucose hydrogen breath test, you will drink a lactose-containing liquid and then have your breath tested for certain gas levels. The direct lactose tolerance test measures your blood sugar directly.

Risks

The lactose tolerance test itself is a relatively safe procedure, with few risks involved. You may experience mild nausea, bloating, and abdominal pain after consuming the lactose-containing liquid.

Why the Test is Performed

The lactose tolerance test is used to diagnose lactose intolerance, which is the inability to digest lactose. Lactose intolerance can lead to a variety of symptoms, such as abdominal cramping, bloating, nausea, and diarrhea.

When to Consider a Lactose Tolerance Test

If you are experiencing any of the symptoms of lactose intolerance, you should talk to your doctor about the possibility of having a lactose tolerance test. Your doctor may also recommend the test if you are at risk for developing the condition, such as those with certain digestive disorders or individuals who are of a certain ethnicity.