How to Get a Lactose Intolerance Test

Testing Available for Lactose Intolerance

Lactose intolerance is usually diagnosed based on symptoms, but a healthcare provider can also perform breath and blood testing. Breath tests are also available as over-the-counter home test kits.

What is Lactose Intolerance?

Lactose is a type of sugar found in milk. Some people lack enough of the lactase enzyme that breaks down lactose. People who do not produce enough lactase may have symptoms after eating dairy products, including diarrhea and abdominal pain.

Symptoms and Diagnosis

Symptoms after eating or drinking dairy products that resolve when you avoid them can be enough to diagnose lactose intolerance. A healthcare provider can diagnose lactose intolerance based on this history, and people often self-diagnose the condition.

Testing Available for Lactose Intolerance

Some people might need or want to be formally tested. This is especially true when it will be helpful to rule out (or rule in) lactose intolerance as a cause of symptoms. Discuss the need for this testing with a healthcare provider.

A breath test or a blood test can be used if testing is done. Uncommon tests include a biopsy from the small intestine (a sample is collected and analyzed in the lab) or a genetic test.

Do You Need a Lactose Intolerance Test?

You may not need testing. You can know that you’re lactose intolerant by noticing symptoms in relation to consuming dairy products. For some people, symptoms such as abdominal pain and diarrhea occur after drinking milk or eating pizza or ice cream. If the symptoms improve when avoiding dairy for a few weeks and then come back after consuming it, it may be reasonable to assume lactose intolerance is an issue.

If there is any concern about a true milk allergy (an immune reaction to milk protein), it is important to see a healthcare provider to get tested for an allergy.

Hydrogen Breath Test

A healthcare provider may perform a hydrogen breath test. This test measures hydrogen in your breath before and after a dose of lactose-containing beverage. Undigested lactose is broken down by bacteria in your gut, creating hydrogen gas and causing higher levels of hydrogen in the breath.

Preparation for the Test

• You must not take antibiotics for two to four weeks before the test.
• Do not smoke or engage in vigorous exercise the day before and the morning of the test.
• Do not eat or drink anything for eight to 12 hours before the test.

Steps to Perform the Test

• Breathe into a balloon-like device that measures hydrogen.
• Drink a solution that contains lactose.
• Every 30 minutes for a few hours, breathe into the measuring device again.

What Results Mean

The treatment for lactose intolerance is avoiding dairy products. However, dairy is a source of nutrients, including calcium and vitamin D, which are needed for bone health and other body functions. If you avoid dairy products, you will need to get those nutrients in another way, through other foods or supplements.

It’s possible to find dairy products with lactose removed or take a lactase supplement immediately before the first sip or bite of lactose-containing foods or drinks. Lactase is an enzyme that can help break down lactose, which might help avoid symptoms.

Next Steps After Diagnosis

People who need to or who decide to omit all dairy products from their diet should work with a healthcare provider to learn how to get enough calcium and vitamin D. Ideally, this would be a dietitian who can help create a healthful eating plan.

Summary

Lactose intolerance is usually diagnosed by symptoms after eating or drinking dairy products. Breath or blood testing is often not needed but may be performed. People who are lactose intolerant and need to avoid dairy should work with a healthcare provider to ensure they are getting enough calcium and vitamin D. Lactose-reduced dairy products and lactase supplements can also be used.