Malabsorption (where your body does not fully absorb nutrients) can lead to a deficiency of certain vitamins and minerals. This can cause conditions such as:
As coeliac disease causes your digestive system to work less effectively, severe cases can sometimes lead to a critical lack of nutrients in your body. This is known as malnutrition, and can result in your body being unable to function normally or recover from wounds and infections.
If you have severe malnutrition, you may become fatigued, dizzy and confused. Your muscles may begin to waste away and you may find it difficult to keep warm. In children, malnutrition can cause stunted growth and delayed development.
Treatment for malnutrition usually involves increasing the number of calories in your diet and taking supplements.
Read more about treating malnutrition.
If you have coeliac disease, you're more likely to also develop lactose intolerance, where your body lacks the enzyme to digest the milk sugar (lactose) found in dairy products. Lactose intolerance causes symptoms such as bloating, diarrhoea and abdominal discomfort.
Unlike gluten in coeliac disease, lactose does not damage your body. But you may get some gut-related symptoms when you eat foods containing lactose because you can't digest it properly.
Lactose intolerance can be effectively treated by not eating and drinking dairy products that contain lactose. You may also need to take calcium supplements – dairy products are an important source of calcium, so you'll need to compensate for not eating them.
Read more about treating lactose intolerance.
Cancer is a very rare but serious complication of coeliac disease.
Someone with coeliac disease has a slightly increased risk of developing certain cancers. Recent research shows that this increased risk is less than previously thought.
If you've been following a gluten-free diet for 3 to 5 years, your risk of developing these types of cancer is the same as that of the general population.
Coeliac disease in pregnancy
Poorly controlled coeliac disease in pregnancy can increase the risk of developing pregnancy-related complications, such as giving birth to a baby with a low birthweight.