CIDPUSA.org Autoimmune diseases
Celiac disease: When the body goes against the grain
Anatomy of celiac disease
The small intestine is lined with fingerlike projections, called villi, that absorb nutrients. In a healthy intestine, they resemble the rough surface of a shag carpet. In celiac disease, the immune system attacks the villi, causing them to flatten and become inflamed. Sometimes only a small portion of the intestine is affected. That's why some people with celiac disease have few or no symptoms and no signs of nutrient deficiencies.
"Celiac" comes from the Latin word for abdomen, but this digestive disease can cause symptoms throughout the body.
Wheat-based foods -- from a bagel for breakfast to pasta for dinner -- are a dietary staple for many people. But for a person with celiac disease, nibbling even a crumb of toast can spell trouble. Celiac disease (also known as celiac sprue) is an inherited intolerance to gluten, the sticky protein found in grains such as wheat, barley, and rye. For people with this condition, eating gluten can trigger immune system attacks that may ravage the lining of the small intestine, causing symptoms that include abdominal pain and bloating, diarrhea, and fatigue. Because the injured intestine can't adequately absorb vital nutrients (such as iron, calcium, and vitamin D), untreated celiac disease can lead to iron deficiency anemia, osteoporosis, lactose intolerance (the inability to digest or absorb lactose, a sugar found in milk and other dairy products), and other problems.
Celiac disease was once thought to be rare, but experts now estimate that in the United States, about 1 in 133 people -- two million in all -- have the disorder. It's more common among people of European ancestry (especially those from Italy, Ireland, and the Scandinavian countries), and it's slightly more prevalent in women.