Lactose tolerance test

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Blood test

Overview

Risks

Results

Lactose tolerance test

Normal Values:

In the breath test, a peak rise in hydrogen content of 12 parts per million over the fasting (pre-test) level is considered positive.

In the blood test, a rise in plasma glucose of more than 30 mg/dl within 2 hours of ingesting the lactose is considered normal. A rise of 20-30 mg/dl is inconclusive. A rise of less than 20 mg/dl is abnormal.

Note: mg/dl = milligrams per deciliter

What abnormal results mean:

Lactase deficiency

An abnormal test should be followed by a glucose tolerance test to exclude an abnormality in absorption of glucose before concluding that there is a lactase deficiency.

Review Date: 1/23/2006
Reviewed By: Jenifer K. Lehrer, MD, Department of Gastroenterology, Frankford-Torresdale Hospital, Jefferson Health System, Philadelphia, PA. Review provided by VeriMed Healthcare Network.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2004 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.