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Did you have a stomachache when you had a glass of milk last night? That may be nothing to be concerned about, but if you feel sick whenever you eat dairy products like milk or ice cream, you may be lactose intolerant.
People with lactose intolerance are unable to fully digest the lactose, or sugar, in milk. Between 30 million and 50 million people in the United States have lactose intolerance, or at least one out of every 10 Americans, says Nemours.
If you think you may be lactose intolerant, speak with your health care provider, who can test you to make a clear diagnosis.
And your health care provider will make sure that another health condition isn't causing your symptoms. Some conditions can cause similar symptoms such as inflammatory bowel disease and irritable bowel syndrome. Then you can talk about how to modify your diet and how to compensate for not eating dairy (you may need to supplement your diet with vitamin D and calcium tablets).
Here are a few signs you may be lactose intolerant.
You feel nauseated whenever you eat dairy.
Some people feel like they have to vomit every time they eat dairy. That's a rare and worst-case scenario. But, if you usually feel nauseated about 30 minutes to 2 hours after you eat milk products, it may be a sign of lactose intolerance.
You're often bloated, gassy and sick after meals.
You're deficient in the enzyme lactase, which usually breaks down the sugars in each lactose molecule so they can be absorbed into the intestine easily. When you don't have lactase, these molecules travel whole down the intestinal tract. Bacteria try to break them down using a process that creates extra gas (fermentation).
Your stomach is making sounds and it hurts.
When you don't have lactase, your body draws a lot of water into your intestine (which is already gassy) to break down lactose on its own. That can leave you with cramps, diarrhea and a gurgling and rumbling belly.
You get symptoms even when you consume foods that don't seem dairy-like.
Have you dismissed the thought of being lactose intolerant because your symptoms happen when you don't eat food from a cow? In fact, many foods contain lactose and you may not even realize it. Some cakes, breads, processed meats, breakfast cereals, soups and salad dressings may contain dairy. Because lactose pops up so frequently in what we eat, it can be hard to track down what dairy items you're consuming. Consider documenting what you eat and looking for any patterns or triggers. And closely examine food labels.
You're of Jewish, Hispanic, Asian, American Indian or African background.
Genetics play a large role in your risk of lactose intolerance, says the Mayo Clinic. Your ancestry can make you more vulnerable to having lactose intolerance than you may realize. It's less common in people of northern or western European background. But it may still occur, according to the U.S. National Library of Medicine.
You were born prematurely.
Infants born prematurely may have reduced levels of lactase. That's because the small intestine doesn't develop lactase-producing cells until late in the third trimester, says the Mayo Clinic. (Note that lactose intolerance is uncommon in babies and young children.)
You've had certain cancer treatments.
If you've received radiation therapy for cancer in your abdomen or have intestinal complications from chemotherapy, the Mayo Clinic says you have an increased risk of lactose intolerance.
You're getting older.
Lactose intolerance is common in adults. Your body starts making less lactase when you're about 2 years old. As you get older, you're more likely to have difficulty digesting dairy foods.