Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services.

Lactose Tolerance Tests

Print this article
Share this page:
Also known as: Hydrogen Breath Test; Lactose Breath Test; Disaccharide Absorption Test; Oral Lactose Tolerance
Formal name: Hydrogen Breath Test; Lactose Tolerance Test
Related tests: Stool Acidity Test, Glucose, Fecal Fat, Xylose Absorption Test, Celiac Disease Tests

At a Glance

Why Get Tested?

To help diagnose lactose intolerance in individuals who have difficulties digesting dairy products, or sometimes as part of an investigation of malabsorption conditions

When to Get Tested?

When you have symptoms such as abdominal pain, bloating, gas, and diarrhea after consuming milk and other dairy products

Sample Required?

A series of breath samples exhaled into a collector, or a series of blood samples drawn from a vein in your arm

Test Preparation Needed?

Overnight fasting is required; nothing but water is permitted. Avoid strenuous activities. You may be instructed to brush your teeth and/or rinse your mouth with water prior to and during the breath test.