Coeliac disease is a condition that causes inflammation in the lining of part of the gut (the small intestine).

Coeliac disease is not a food allergy or a food intolerance. It is an autoimmune disease. The immune system makes white blood cells (lymphocytes) and antibodies to protect against foreign objects such as bacteria, viruses, and other germs. In an autoimmune disease, the immune system mistakes part or parts of the body as foreign. Other autoimmune diseases include type 1 diabetes, rheumatoid arthritis and some thyroid disorders.

The lining of the small intestine contains millions of tiny tube-shaped structures called villi. These help food and nutrients to be digested more effectively into the body. But, in people with coeliac disease, the villi become flattened as a result of the inflammation. This means that food and nutrients are not so readily digested by the body.

Who does coeliac disease affect?

Coeliac disease affects about 1 in 100 people in the UK. Anyone, at any age, can develop coeliac disease. It is a condition that used to be associated with young children. However, it is now much more commonly diagnosed in adults. It is most commonly diagnosed in people aged between 50 and 69. About 1 in 4 cases are first diagnosed in people aged over 60.

Coeliac disease often runs in families. If you have a close family member who has coeliac disease (a brother, sister, parent or child) then you have a 1 in 10 chance of developing coeliac disease. It is also more common in people who have other autoimmune diseases - for example, some thyroid diseases, rheumatoid arthritis and type 1 diabetes.