Celiac disease is an inherited, autoimmune disease in which the lining of the small intestine is damaged from eating gluten and other proteins found in wheat, barley, rye, and possibly oats.

The exact cause of celiac disease is unknown. The intestines contain projections (called villi) that absorb nutrients. In undiagnosed or untreated celiac disease, these villi become flattened. This affects the ability to absorb nutrients properly.

The disease can develop at any point in life, from infancy to late adulthood.

Those with a family member with celiac disease are at greater risk for developing the disease. The disorder is most common in Caucasians and those of European ancestry. Women are affected more commonly than men.

There are numerous diseases and conditions associated with celiac disease, including:

• Anemia
• Autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus
• Certain types of intestinal cancer
• Dermatitis herpetiformis
• Down syndrome
• Lactose intolerance
• Miscarriage or unexplained infertility
• Neurological conditions
• Osteoporosis or osteopenia
• Thyroid disease
• Type 1 diabetes

The symptoms of celiac disease can vary significantly from person to person. This is part of the reason the diagnosis is frequently delayed. For example, one person may have constipation, a second may have diarrhea, and a third may have no irregularity in stools.

A partial listing of gastrointestinal symptoms:

• Abdominal pain
• Abdominal distention, bloating, gas, indigestion
• Constipation
• Decreased appetite (may also be increased or unchanged)
• Diarrhea, chronic or occasional
• Lactose intolerance (common upon diagnosis, usually goes away following treatment)
• Nausea and vomiting
• Stools that float, are foul smelling, bloody, or “fatty”
• Unexplained weight loss (although people can be overweight or of normal weight upon diagnosis)

A partial listing of nonintestinal symptoms:

• Anemia (low blood count)
• Bone and joint pain
• Bone disease (osteoporosis, kyphoscoliosis, fracture)
• Breathlessness (due to anemia)
• Bruising easily
• Dental enamel defects and discoloration
• Depression
• Fatigue
• Growth delay in children
• Hair loss
• Hypoglycemia (low blood sugar)
• Irritability and behavioral changes
• Malnutrition
• Mouth ulcers
• Muscle cramps
• Nosebleed
• Seizures
• Short stature, unexplained
• Skin disorders (dermatitis herpetiformis)
• Swelling, general or abdominal
• Vitamin or mineral deficiency, single or multiple nutrient (for example, iron, folate, vitamin K)

• A complete blood count (CBC) may show signs of anemia. It is important to determine the cause if anemia is detected.
• An increase in alkaline phosphatase level may indicate bone loss.
• Low cholesterol and albumin levels may be signs of malabsorption and malnutrition.
• Mildly raised liver enzymes and abnormal blood clotting may also be noted.

Blood tests can detect several special antibodies. The health care provider will order these antibody test if celiac sprue is suspected. If the tests are positive, upper endoscopy is usually performed to sample a piece of tissue (biopsy) from the first part of the small intestine (duodenum).

Genetic testing of the blood is also available to help determine who may be at risk for celiac disease.

An endoscopy with enteroscopy, particularly of the lower sections of the intestine most commonly affected, will show a flattening of the villi.

A follow-up biopsy or blood work may be ordered several months after the diagnosis and treatment. These confirm the disease. Normal results mean that you have responded to treatment, thereby confirming the diagnosis. However, this does not suggest that the disease has been cured.

You must follow a lifelong gluten-free diet. This allows the intestinal villi to heal. Eliminate foods, beverages, and medications that contain wheat, barley, rye, and possibly oats.

You must read food and medication labels carefully to look for hidden sources of these grains and their derivatives. Since wheat and barley grains are found abundantly in the American diet, keeping to this diet is challenging. With education and planning, you will achieve the goal of healing.

You should NOT begin the gluten-free diet before a diagnosis is made. Doing so will affect future testing for the disease.

The health care provider may prescribe vitamin and mineral supplements to correct nutritional deficiencies. Occasionally, corticosteroids (such as prednisone) may also be prescribed for short-term use or if you have refractory sprue. Following a well-balanced, gluten-free diet is generally the only treatment needed to stay well.

Upon diagnosis, get help from a registered dietitian who specializes in celiac disease and the gluten-free diet. A support group may also help you cope with the disease and diet.

For additional information and support, see the organizations listed in celiac disease resources.

Removing all damaging grains from the diet is the most important measure you can take to become healthy. If you follow the diet strictly, you can expect to lead a long, healthy life -- if permanent damage did not occur before diagnosis.

You must carefully and continuously follow the gluten-free diet. When untreated, the disease can cause life-threatening complications.

Delaying diagnosis or not following the diet puts you at risk for related conditions such as:

• Autoimmune disorders
• Certain types of intestinal cancer
• Fractures
• Infertility
• Miscarriage
• Osteoporosis

Call your health care provider if you have symptoms of celiac disease.

Because the exact cause is unknown, there is no known way to prevent the development of celiac disease. However, being aware of the risk factors (such as having a family member with the disorder) may increase your chances of early diagnosis, treatment, and a long, healthy life.

Hutchinson JM, Robins G, Howdle PD. Advances in coeliac disease. Curr Opin Gastroenterol. 2008;24:129-134.

Green PH, Cellier C. Celiac disease. N Engl J Med. 2007;357:1731-1743.