Are you struggling with an upset stomach after you eat a scoop of ice cream?Marc Leclerc You might be lactose intolerant.

People who are lactose intolerant are unable to digest lactose, a sugar found in milk and milk products. The good news: if you think you might be lactose intolerant, you’re not alone. According to Boston Children’s Hospital, 30 to 50 million Americans have this condition. The bad news: you might need to change your eating habits.

If you think you're lactose intolerant, here’s exactly what this means for your future. 

What is lactose intolerance?

People develop lactose intolerance when their bodies don’t make enough of the enzyme lactase for the amount of dairy they consume, says Dr. Christopher Schmoyer, an assistant professor of Gastroenterology at the Perelman School of Medicine at the University of Pennsylvania.

You need lactase to break down lactose sugar into its two smaller, digestible components. But our bodies tend to produce less of this enzyme as we age. This causes the sugar to build up in our gastrointestinal tract and leads to uncomfortable symptoms.

Typical symptoms associated with lactose intolerance include gas, bloating, abdominal pain and diarrhea. In more severe cases, people may experience nausea and vomiting.

Is it OK to be lactose intolerant?

It’s totally normal to be lactose intolerant as an adult, says Schmoyer. “Our bodies really are only meant to drink milk and digest it when we’re babies. When we’re in infancy and the first couple years of our life is when our bodies produce that lactase enzyme at the highest levels,” he explains. “So, it’s a normal thing that over time our own body's ability to make that enzyme just decreases.” The ability to digest lactose in adulthood is actually the result of genetic mutations that developed thousands of years ago.

What foods to avoid if you’re lactose intolerant

If you’re experiencing age-related lactose intolerance, you might want to change your eating habits. To avoid negative symptoms, cut out foods high in lactose. Examples include many dairy products and even some prepared foods, according to Healthline.

What triggers your symptoms may be different from another person. You may be able to consume some lactose, says Amy Reed, a registered dietitian at Cincinnati Children’s Hospital Medical Center and a spokesperson for the Academy of Nutrition and Dietetics. Try different dairy brands, dairy foods and amounts of dairy to find what your threshold is. There are also solutions you can try. Look for lactose-free milk and dairy products as well as enzyme supplements, like Lactaid, which help you digest lactose.

While age-related lactose intolerance is essentially permanent, there are options for you. So, grab that bowl of ice cream (and an enzyme supplement). You deserve a sweet treat.

How is almond milk made?It's surprisingly simple.