People with lactose intolerance have trouble digesting lactose, the natural sugar found in dairy foods. This is because their bodies do not have enough of the enzyme lactase.
Lactose intolerance is not common in young children because most people are born with enough lactase. However, in some people, the amount of lactase in their body drops over their lifetime. This is especially common in non-Caucasians and other populations that don't traditionally include dairy products in their diets.
Symptoms of lactose intolerance can include:
Symptoms can be mild or severe, usually depending on how much lactose a person has eaten or drank, and how much lactase is in their body.
Lactose intolerance is not usually an all-or-nothing condition: the reduction in lactase production and the amount of lactose that can be tolerated varies from person to person. Managing the condition consists of minimizing the occurrence and severity of symptoms. Four general principles to relieve symptoms include:
Most people with lactose intolerance do not require a completely lactose-free diet. Studies show that there are some things people with lactose intolerance can do to have fewer symptoms of lactose intolerance: