What Exactly Is Lactose Intolerance?
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What Exactly Is Lactose Intolerance?

Lactose intolerance is the inability to digest lactose, the sugar primarily found in milk and dairy products.

Lactose intolerance is the inability to digest lactose, the sugar primarily found in milk and dairy products. It is caused by a shortage in the body of lactase, an enzyme produced by the small intestine, which is needed to digest lactose. While lactose intolerance is not dangerous, its symptoms can be distressing. When lactose moves through the large intestine (colon) without being properly digested, it can cause uncomfortable symptoms such as gas, pain in the belly, 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. The biggest challenges for people who are lactose-intolerant are knowing how to eat to avoid discomfort and getting enough calcium to maintain healthy bones.

What Are the Symptoms of Lactose Intolerance?

Symptoms of lactose intolerance can be mild or severe, depending on how much lactase your body makes. Symptoms usually begin 30 minutes to 2 hours after eating or drinking milk or milk products. The severity of symptoms varies, depending on the amount of lactose an individual person can tolerate. Some people may be sensitive to extremely small amounts of lactose-containing foods while others can eat larger amounts before they notice symptoms.

If you have lactose intolerance, your symptoms may include:

  • Bloating
  • Pain or cramps in the lower belly.
  • Gurgling or rumbling sounds in the lower belly.
  • Gas
  • Loose stools or diarrhea. Sometimes the stools are foamy.
  • Nausea or Throwing up.

Who Gets Lactose Intolerance?

Lactose intolerance is extremely common. It is estimated that 30 to 50 million Americans have some degree of lactose intolerance. 

What Causes Lactose Intolerance?

For most people, lactose intolerance develops naturally as they grow older. The small intestine begins to produce less lactase in everyone after age two. Certain digestive diseases such as Crohn's disease, celiac disease ( a digestive disease that damages the small intestine and interferes with absorption of nutrients from food) and injuries to the small intestine can also reduce the amount of lactase available to process lactose properly.

How is Lactose Intolerance Diagnosed?

Usually lactose intolerance is diagnosed based solely on symptoms and relief of those symptoms when avoiding dairy products. However, health care providers can perform certain tests to help confirm the diagnosis. Many doctors will ask patients who suspect they have lactose intolerance to avoid milk and dairy products for one or two weeks to see if their symptoms subside, and will then confirm the diagnosis with the hydrogen breath test, a lactose intolerance test or a stool test.

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Comments (1)

Good explanation of what lactose intolerance is. Well done Tracy.