How to Diagnose Lactase Deficiency

Lactose intolerance, a condition which makes it difficult to digest dairy products, is caused by lactase deficiency. Lactase is an enzyme that allows you to digest the sugars found in dairy products. Doctors often have patients follow a simple procedure to diagnose lactase deficiency with a breath test.

Instructions

• 1

  Fast and avoid heavy exercise for at least 8 hours before the test.

• 2

  Breathe out into a container the doctor gives you so the doctor can see how much hydrogen is in your breath when you haven't had foods containing lactose. Normally, you have only a small amount of hydrogen in your breath.

• 3

  Drink approximately 50g of flavored liquid containing lactose.

• 4

  Wait while you digest the lactose, as directed by your doctor.

• 5

  Exhale into a container the doctor gives you. If the hydrogen in your breath at the end of the test is 12 parts per million more than at the beginning of the test, you have lactase deficiency. The doctor may order more tests to find out what is causing it.