Celiac disease is a chronic (long-term) digestive and immune disorder that damages your small intestine. The damage may prevent your body from absorbing vitamins, minerals, and other nutrients from the food you eat. This can lead to malnutrition and other serious health problems

Celiac disease is triggered by eating foods that contain gluten. Gluten is a protein found in wheat, barley, rye, and other grains. It may also be in other products like vitamins and supplements, hair and skin products, toothpastes, and lip balm.

Celiac disease is different from gluten sensitivity. Both involve problems with gluten and can cause some of the same symptoms, such as abdominal (belly) pain and fatigue. But gluten sensitivity does not damage the small intestine like celiac disease does.

Wheat allergy, a type of food allergy, is also different. With both celiac disease and wheat allergy, your immune system is reacting to wheat. But with wheat allergy, you can have some different symptoms, such as itchy eyes or trouble breathing. And a wheat allergy will not cause long-term damage to the small intestine.

The exact cause of celiac disease is not known. Research suggests that celiac disease only happens in people who have certain genes and eat food that contains gluten. Researchers are studying other factors that may play a role in causing the disease.

Celiac disease is more common if you:

• Have a family member who has the disease
• Have Down syndrome, Turner syndrome, or Williams syndrome
• Are White
• Are female

The symptoms of celiac disease can be different from person to person. Sometimes the symptoms may come and go. Some people may not notice any symptoms.

Some of the possible symptoms affect your digestive system. Digestive symptoms are more common in children than in adults. The digestive symptoms include:

• Bloating (feeling fullness or swelling in your belly)
• Chronic (long-term) diarrhea or greasy, bulky, unusually bad-smelling stool (poop)
• Constipation
• Gas
• Lactose intolerance because of damage to the small intestine
• Nausea and vomiting
• Pain in the abdomen (belly)
• Weight loss in adults, or not enough weight gain in children

Some people with celiac disease have symptoms that affect other parts of the body, such as:

• Fatigue
• Depression and anxiety
• Irritability (in children)
• Dermatitis herpetiformis, an itchy rash with blisters (mainly in adults)
• Bone or joint pain
• Symptoms involving the mouth, such as canker sores or dry mouth

Over time, celiac disease can cause other health problems, especially if it is not treated. These problems can include:

• Malnutrition
• Anemia, especially iron-deficiency anemia
• Bone loss
• Nervous system problems such as headaches, balance problems, or peripheral neuropathy
• Reproductive problems, such as missed menstrual periods and miscarriages in women and infertility in men and women

If you have symptoms of celiac disease, your health care provider will look for signs that you might have celiac disease. To do this, your provider will get your medical and family history and do a physical exam.

If your provider thinks that you could have celiac disease, you will have some tests. Providers most often use blood tests and biopsies of the small intestine to diagnose celiac disease. The biopsy would be done during an upper gastrointestinal (GI) endoscopy. For this procedure, your provider uses an endoscope (a flexible tube with a camera) to see the lining of your esophagus, stomach, and small intestine. It also allows your provider to take a sample of tissue for a biopsy.

The treatment for celiac disease is following a gluten-free diet for the rest of your life. Sticking with a gluten-free diet will treat or prevent many of the symptoms and other health problems caused by celiac disease. In most cases, it can also heal damage in the small intestine and prevent more damage.

Your provider may refer you to a registered dietician (a nutrition expert) who can help you learn how to eat a healthy diet without gluten. You will also need to avoid all hidden sources of gluten, such as certain supplements, cosmetics, toothpaste, etc. Reading product labels can sometimes help you avoid gluten. If a label doesn't tell you what is in a product, check with the company that makes the product for an ingredients list. Don't just assume that a product is gluten-free if it doesn't mention it.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases