Lactose Intolerance Also called: Dairy product intolerance, Lactase deficiency, Milk intolerance Summary Lactose intolerance means that you cannot digest foods with lactose in them. Lactose is the sugar found in milk and foods made with milk. After eating foods with lactose in them, you may feel sick to your stomach. You may also have Gas Diarrhea Swelling in your stomach Your doctor may do a blood, breath or stool test to find out if your problems are due to lactose intolerance. Lactose intolerance is not serious. Eating less food with lactose, or using pills or drops to help you digest lactose usually helps. You may need to take a calcium supplement if you don’t get enough of it from your diet, since milk and foods made with milk are the most common source of calcium for most people. NIH: National Institute of Diabetes and Digestive and Kidney Diseases National Institute of Diabetes and Digestive and Kidney Diseases Clinical Trials ClinicalTrials.gov: Lactose Intolerance National Institutes of Health Related Issues Dairy Dilemma: Are You Getting Enough Calcium? National Institutes of Health Food Intolerance vs. Food Allergy: What’s the Difference? Mayo Foundation for Medical Education and Research How Many People Are Affected or At Risk for Lactose Intolerance? National Institute of Child Health and Human Development Milk Allergy Mayo Foundation for Medical Education and Research What Causes Lactose Intolerance? National Institute of Child Health and Human Development What FDA Learned About Dark Chocolate and Milk Allergies Food and Drug Administration What People with Lactose Intolerance Need to Know about Osteoporosis National Institute of Arthritis and Musculoskeletal and Skin Diseases Genetics Genetics Home Reference: lactose intolerance National Library of Medicine Diagnosis and Tests How Is Lactose Intolerance Diagnosed? National Institute of Child Health and Human Development Lactose Tolerance Tests American Association for Clinical Chemistry Living With How Is Lactose Intolerance Managed? National Institute of Child Health and Human Development Start Here Lactose Intolerance Mayo Foundation for Medical Education and Research Lactose Intolerance National Institute of Diabetes and Digestive and Kidney Diseases Problems Digesting Dairy Products? Food and Drug Administration What I Need to Know about Lactose Intolerance National Institute of Diabetes and Digestive and Kidney Diseases What Is Lactose Intolerance? National Institute of Child Health and Human Development Patient Handouts Lactose Intolerance National Institute of Diabetes and Digestive and Kidney Diseases Array Lactose intolerance Children Lactose Intolerance (For Kids) Nemours Foundation Lactose Intolerance (For Parents) Nemours Foundation Teenagers Lactose Intolerance (For Teens) Nemours Foundation Lactose Intolerance: A Guide for Teens Children’s Hospital Boston Encyclopedia Lactose tolerance tests Find an Expert National Institute of Diabetes and Digestive and Kidney Diseases National Institute of Diabetes and Digestive and Kidney Diseases Journal Articles Lactose Intolerance