Title: Lactose intolerance - Wikipedia
Headings: Lactose intolerance
Lactose intolerance
Contents
Terminology
Signs and symptoms
Causes
Primary hypolactasia
Secondary hypolactasia
Primary congenital alactasia
Diagnosis
Hydrogen breath test
Blood test
Stool acidity test
Intestinal biopsy
Stool sugar chromatography
Genetic diagnostic
Management
Dietary avoidance
Milk substitutes
Lactase supplements
Rehabituation to dairy products
Epidemiology
History
History of research
Other animals
See also
References
External links

Content: Their severity typically depends on the amount a person eats or drinks. Lactose intolerance does not cause damage to the gastrointestinal tract. Lactose intolerance is due to the lack of the enzyme lactase in the small intestines to break lactose down into glucose and galactose. There are four types: primary, secondary, developmental, and congenital. Primary lactose intolerance occurs as the amount of lactase declines as people age. Secondary lactose intolerance is due to injury to the small intestine. Such injury could be the result of infection, celiac disease, inflammatory bowel disease, or other diseases. Developmental lactose intolerance may occur in premature babies and usually improves over a short period of time. Congenital lactose intolerance is an extremely rare genetic disorder in which little or no lactase is made from birth.