Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food. People who have celiac disease cannot tolerate gluten, a protein in wheat, rye, and barley. Gluten is found mainly in foods but may also be found in everyday products such as medicines, vitamins, and lip balms.
Celiac disease is genetic, meaning it runs in families. Sometimes the disease is triggered—or becomes active for the first time—after surgery, pregnancy, childbirth, viral infection, or severe emotional stress.
More than 2 million people in North America have the disease, or about 1 in 133 people. Among people who have a first-degree relative—a parent, sibling, or child—diagnosed with celiac disease, as many as 1 in 22 people may have the disease. Celiac disease is also more common among people with other genetic disorders including Down syndrome and Turner syndrome, a condition that affects girls’ development.
Celiac disease is both a disease of malabsorption—meaning nutrients are not absorbed properly—and an abnormal immune reaction to gluten. When people with celiac disease eat foods or use products containing gluten, their immune system responds by damaging or destroying villi—the tiny, fingerlike protrusions lining the small intestine. Villi normally allow nutrients from food to be absorbed through the walls of the small intestine into the bloodstream. Without healthy villi, a person becomes malnourished, no matter how much food one eats.
Symptoms of celiac disease vary from person to person. Symptoms may occur in the digestive system or in other parts of the body. Digestive symptoms are more common in infants and young children and may include:
- Abdominal bloating and pain
- Chronic diarrhea
- Pale, foul-smelling, or fatty stool
- Weight loss
Malabsorption of nutrients during the years when nutrition is critical to a child’s normal growth and development can result in other problems such as failure to thrive in infants, delayed growth and short stature, delayed puberty, and dental enamel defects of the permanent teeth.
Adults are less likely to have digestive symptoms and may instead have one or more of the following:
- Unexplained iron-deficiency anemia
- Bone or joint pain
- Bone loss or osteoporosis
- Depression or anxiety
- Tingling numbness in the hands and feet
- Missed menstrual periods
- Infertility or recurrent miscarriage
- Canker sores inside the mouth
- An itchy skin rash called dermatitis herpetiformis
People with celiac disease may have no symptoms but can still develop complications of the disease over time. Long-term complications include malnutrition—which can lead to anemia, osteoporosis, and miscarriage, among other problems—liver diseases, and cancers of the intestine.
People with celiac disease tend to have other diseases in which the immune system attacks the body’s healthy cells and tissues. The connection between celiac disease and these diseases may be genetic. They include:
- Type 1 diabetes
- Autoimmune thyroid disease
- Autoimmune liver disease
- Rheumatoid arthritis
- Addison’s disease, a condition in which the glands that produce critical hormones are damaged
- Sjögren’s syndrome, a condition in which the glands that produce tears and saliva are destroyed
The only treatment for celiac disease is a gluten-free diet. For most people, following this diet will stop symptoms, heal existing intestinal damage, and prevent further damage. Improvement begins within days of starting the diet. The small intestine usually heals in 3 to 6 months in children but may take several years in adults. A healed intestine means a person now has villi that can absorb nutrients from food into the bloodstream.
Some people with celiac disease show no improvement on the gluten-free diet. The most common reason for poor response to the diet is that small amounts of gluten are still being consumed. Hidden sources of gluten include additives such as modified food starch, preservatives, and stabilizers made with wheat. And because many corn and rice products are produced in factories that also manufacture wheat products, they can be contaminated with wheat gluten.
Rarely, the intestinal injury will continue despite a strictly gluten-free diet. People with this condition, known as refractory celiac disease, have severely damaged intestines that cannot heal. Because their intestines are not absorbing enough nutrients, they may need to receive nutrients directly into their bloodstream through a vein, or intravenously. Researchers are evaluating drug treatments for refractory celiac disease.