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Lactose Intolerance - Topic Overview
What is lactose intolerance?
Lactose intolerance means the body cannot easily digest lactose, a type of natural sugar found in milk and dairy products.
When lactose moves through the
large intestine
(colon) without being properly digested, it can cause
uncomfortable symptoms such as gas, belly pain, and bloating. Some people with
lactose intolerance cannot digest any milk products, while others can eat or
drink small amounts of milk products or certain types of milk products without
problems.
Lactose intolerance is common in adults. It occurs more often in Native Americans and people of Asian, African, and South American descent than among people of European descent.
A big challenge for people who are lactose-intolerant is learning how to eat to avoid discomfort and to get enough calcium for healthy bones.
What causes lactose intolerance?
Lactose intolerance occurs when the
small intestine does not make enough of an
enzyme called lactase. Your body needs lactase to
break down, or digest, lactose.
Lactose intolerance most commonly runs in families, and symptoms usually develop during the teen or adult years. Most people with this type of lactose intolerance can eat some milk or dairy products without problems.
Sometimes the small intestine stops making lactase after a short-term illness such as the stomach flu, or as part of a lifelong disease such as cystic fibrosis, or after surgery to remove a part of the small intestine. In these cases, the problem can be either permanent or temporary.
In rare cases, newborns are lactose-intolerant. A person born with lactose intolerance cannot eat or drink anything with lactose.
Some premature babies have temporary lactose intolerance because they are not yet able to make lactase. After a baby begins to make lactase, the condition generally goes away.
What are the symptoms?
Symptoms of lactose intolerance can be mild to severe, depending on how much lactase your body makes. Symptoms usually begin 30 minutes to 2 hours after you eat or drink milk products. If you have lactose intolerance, your symptoms may include:
- Bloating.
- Pain or cramps.
- Gurgling or rumbling sounds in your belly.
- Gas.
- Loose stools or diarrhea.
- Throwing up.
Many people who have gas, belly pain, bloating, and diarrhea suspect they may be lactose-intolerant. The best way to check this is to avoid eating all milk and dairy products to see if your symptoms go away. If they do, then you can try adding small amounts of milk products to see if your symptoms come back.
If you feel sick after drinking a glass of milk one time, you probably do not have lactose intolerance. But if you feel sick every time you have milk, ice cream, or another dairy product, you may have lactose intolerance.
Sometimes people who have never had problems with milk or dairy products suddenly have lactose intolerance. This is more common as you get older.
WebMD Medical Reference from Healthwise
Lactose Intolerance Topics
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