Lactose intolerance

Alternative Names

Lactase deficiency; Milk intolerance; Disaccharidase deficiency; Dairy product intolerance

Definition of Lactose intolerance

Lactose intolerance is the inability to digest lactose. Lactose is a type of sugar found in milk and other dairy products.

Causes, incidence, and risk factors

Lactose intolerance happens when the small intestine does not make enough of the enzyme lactase. Enzymes help the body absorb foods. Not having enough lactase is called lactase deficiency.

Symptoms

Symptoms often occur 30 minutes to 2 hours after you eat or drink milk products, and are often relieved by not eating or drinking milk products. Large doses of milk products may cause worse symptoms.

Signs and tests

Other intestinal problems, such as irritable bowel syndrome, may cause the same symptoms as lactose intolerance.

Treatment

Decreasing or removing milk products from the diet usually improves the symptoms.

Expectations (prognosis)

Symptoms usually go away when you remove milk products or other lactose containing products from the diet.

Review

David C. Dugdale, III, MD. Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 7/7/2010

Digestive system organs

ADAM Medical Encyclopedia

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