Lactose Intolerance

You might suspect you’re lactose intolerant if you notice a pattern of gastrointestinal symptoms after you eat dairy products. However, many people with lactase deficiency can tolerate some lactose, sometimes. If you’re not sure whether lactose is affecting you, visit a healthcare provider.

How do you test for lactose intolerance?

Healthcare providers have several ways of testing for lactose intolerance. Common tests include:

• Hydrogen breath test. A breath test measures the amount of hydrogen and methane gases in your breath when you exhale. Bacteria in your colon produce these gases. If you have higher levels of these gases after ingesting lactose, it’s because your gut bacteria are fermenting the lactose, producing gas in your colon that can later be measured in your breath.
• Blood sugar test. If a breath test is inconclusive, a healthcare provider might suggest a blood glucose (blood sugar) test. This test measures the sugar content in your blood before and after you ingest lactose. If your blood sugar doesn’t rise, it shows you’re not absorbing the lactose.
• Stool acidity test. Healthcare providers use this test for small children and infants. After feeding a child lactose, they’ll take a poop (stool) sample and analyze the content. Levels of lactic acid and other byproducts in the sample can show whether or not the body is absorbing the lactose.