Celiac disease is a digestive disease that damages the small intestine and interferes with the absorption of nutrients. People with celiac disease cannot tolerate gluten, a protein in wheat, rye and barley. Gluten is also found in everyday products such as medications, vitamins, shampoos and lip balm.

Celiac disease is not an allergic reaction but an immune response; the immune system reacts to the gluten, attacking and damaging villi, the tiny, fingerlike protrusions lining the small intestine. Villi normally allow nutrients to be absorbed through the walls of the small intestine. Without healthy villi, a person becomes malnourished, no matter how much food is consumed.

Celiac disease affects people all around the world and is also known as celiac sprue, non-tropical sprue and gluten-sensitive enteropathy. Originally thought to be a rare childhood disease, it is now known as a genetic disorder. Surgery, pregnancy, childbirth, viral infection or severe emotional stress can trigger the disease for the first time.

More than 2 million Americans have celiac disease — about one in 33 people. It is more common among people with other genetic disorders such as Down syndrome and Turner’s syndrome, a condition that affects girls’ development. People with celiac disease tend to have other diseases involving the immune system, such as Type 1 diabetes, autoimmune thyroid disease, rheumatoid arthritis, Addison’s disease and Sjögren’s syndrome.

The symptoms of celiac disease vary for each person and can occur in the digestive system or other areas. Symptoms include diarrhea, constipation or both; abdominal pain and cramping; abdominal swelling or bloating; weight loss; bone or joint pain; chronic fatigue; mood changes, irritability and depression; canker sores inside the mouth; an itchy skin rash; and tooth enamel problems. Some people may not have symptoms but can develop complications over time such as anemia, osteoporosis, miscarriage, infertility, liver disease or cancers of the intestine.

The length of time a person is breastfed, the age a person starts to ingest gluten and the amount of gluten consumed are three factors thought to play a role in when and how celiac disease appears. Some studies show the longer a person is breastfed, the later the symptoms appear. Symptoms also vary with a person’s age and the degree of damage to the intestine. Many adults have the disease for a decade or more before they are diagnosed. The longer a person goes undiagnosed and untreated, the greater the chance of longterm complications.

Celiac disease is diagnosed by an assessment of symptoms, a health history and physical exam. Blood tests look for specific proteins and anemia and rule out other problems. A gastroenterologist performs an upper endoscopy with biopsy to check for damage in your stomach and intestine. Genetic tests of blood or saliva samples seek to identify problems with specific genes linked to celiac disease.

If you are diagnosed with celiac disease, a registered dietician can recommend a gluten-free diet, teaching you about food selection, label reading and other strategies. Schedule an annual follow-up with your health care provider to make sure your condition is under control. If needed, your provider can refer you to other health care providers or support groups to help you cope.

While the most common source of gluten is wheat flour, it is found in many foods you might not consider, so reading labels is important. Your diet does not need to be boring. Many foods are naturally gluten-free, and there are now gluten-free forms of many foods. Keep in mind that products labeled “wheat-free” may not be gluten-free.

Living gluten-free means always being aware. Even if you are very careful, mistakes can happen. The food you eat cannot come in contact with gluten; meals must be made with utensils (knives, cutting boards, toasters) that have not touched foods containing gluten. Shared condiments may have crumbs that contain gluten. Whenever you eat food prepared by others, ask how it was made.

Some medications and vitamin supplements contain gluten, so ask your pharmacist. Some shampoos, lotions, make-up, glues, soaps and other products contain gluten. It is possible to ingest gluten when using these products. Wash your hands before preparing food or eating, since there could be gluten on your hands.

While there are many gluten-free foods on the market and restaurants are beginning to offer gluten-free menus, living gluten-free is still a big lifestyle change. Joining a celiac support group can offer emotional support and tips on making it easier for you and the people you live with.

With some planning, you can eat safely when traveling. Ask your hotel or resort if they offer gluten-free food. Pack gluten-free snacks (such as peanut butter, foil packs of tuna, gluten-free crackers or pretzels) to eat in the airport or on the plane or ship. Order gluten-free meals for the flight or cruise; when you board, remind the crew of your needs. When traveling by car, take a cooler for perishable gluten-free items such as cheese, meat and yogurt. The Gluten-Free Restaurant Awareness Program keeps an online database of restaurants and products in North America that meet strict gluten-free requirements for food preparation and service.

The content of this article is for informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition.