Skip to content

Signs You are Lactose Intolerant, According to Physicians

People affected by lactose intolerance may experience uncomfortable symptoms.
FACT CHECKED BY Emilia Paluszek

Thanks to TV commercials, you've probably heard of lactose intolerance, one of those food sensitivities that can make meals take an uncomfortable turn. But what is it, exactly? Is it an allergy? Are some people more likely to have it than others? These are the signs you have lactose intolerance, and what you can do about them, according to physicians. Read on to find out more—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


What Is Lactose Intolerance?

Woman holding glass of milk having bad stomach ache

Lactose intolerance happens when the body is unable to digest the sugar (or lactose) in milk. People affected by lactose intolerance may experience uncomfortable symptoms after consuming dairy products, including milk, cheese, or ice cream. 


What Are The Signs Of Lactose Intolerance?


"Lactose intolerance can have a very wide and non-specific range of symptoms, making it difficult to distinguish from other stomach complaints," says Andrew Boxer, MD, a gastroenterologist at Jersey City Medical Center. "Patients often experience bloating, abdominal pain, and diarrhea after eating foods that are high in lactose, such as milk, ice cream, and yogurt."

Digestive symptoms, which are most common, can appear anywhere from 30 minutes to 2 hours after eating, says Carrie Lam, MD, FAAMFM, ABAARM, a California-based family medicine physician. "If you have ongoing intolerance, you may also experience migraines and headaches," she adds. "This occurs because of undigested food particles that linger in your body long after you've last eaten dairy products. This problem may be even worse if you have a leaky gut."

Lactose intolerance can appear at any age, but it is more common in older people, says Lam. "It isn't an allergy and doesn't cause the immune system to overreact. As a result, the symptoms of intolerance are usually far less serious than allergy symptoms. However, it may not feel that way at the time."

RELATED: If You Do This Every Morning, Get Checked For Diabetes


How Is Lactose Intolerance Diagnosed?

woman consulting with female doctor

If you suspect you have lactose intolerance, see your doctor. It can be diagnosed with simple tests. "Most laboratories will offer tests for lactose intolerance," says Boxer. "This is usually measured either by measuring hydrogen in the breath or glucose levels in the blood."

RELATED: Signs You Have Celiac Disease, Say Physicians


What Causes Lactose Intolerance, and How Can You Treat It?

Woman taking supplements.

"Lactose intolerance is typically caused by not enough lactase, a digestive enzyme, being produced in the small intestine," says Boxer. "Patients can try taking an over-the-counter medicine that contains lactase before eating dairy products to see whether their symptoms improve." 

These products are sold under brand names like Lactaid, and they come in pill and liquid form. You can take the pills before having a meal or snack that contains lactose, or add drops to a container of milk.

You can also try:

  • Eating smaller amounts of dairy 
  • Consuming dairy only at mealtimes
  • An elimination diet—removing dairy foods you think are problematic—to pinpoint the sources of your lactose intolerance
  • Sticking to dairy foods that cause you less discomfort

But it's always a good idea to check in with your doctor if something seems off. "I always encourage someone to seek the advice of a medical professional if their symptoms seem excessive or unusual, or if something does not feel right to them," says Boxer.

RELATED: Signs You Have Heartburn, Say Physicians


Milk Substitutes an Option

starbucks oat milk drinks

Some nutrition experts recommend avoiding animal milk altogether. "Lactose intolerance is more common than realized," says Dana Ellis Hunnes, PhD, MPH, RD, a senior dietitian at UCLA Medical Center, and author of the book Recipe for Survival. "As much as two-thirds of adults around the world are lactose intolerant. As we age, we no longer need animal milk. We are one of the only—if not the only—species that continues to drink milk after weaning, and we lose the need for the lactase enzyme." 

Hunnes recommends substituting animal milk for any of the plant-based, non-dairy options that are available (like almond, soy, or oat milks). These milks are fortified with calcium and vitamins D and B12, providing a similar nutrient profile to dairy milk (along with environmental benefits, as fewer resources and emissions are involved in their production). 

Michael Martin
Michael Martin is a New York City-based writer and editor. Read more about Michael
Filed Under