What is celiac disease?

Celiac disease is an immune disorder in which people cannot tolerate gluten because it damages the inner lining of their small intestine and prevents it from absorbing nutrients. The small intestine is the tubeshaped organ between the stomach and large intestine. Gluten is a protein found in wheat, rye, and barley and occasionally in some products such as vitamin and nutrient supplements, lip balms, and certain medications.

The immune system is the body's natural defense system and normally protects the body from infection. However, when a person has celiac disease, gluten causes the immune system to react in a way that can cause intestinal inflammation—irritation or swelling—and long-lasting damage.

When people with celiac disease eat foods or use products containing gluten, their immune system responds by damaging or destroying villi—the tiny, fingerlike projections on the inner lining of the small intestine. Villi normally absorb nutrients from food and pass the nutrients through the walls of the small intestine and into the bloodstream. Without healthy villi, people can become malnourished, no matter how much food they eat.

What are the signs and symptoms of celiac disease?

A person may experience digestive signs and symptoms, or symptoms in other parts of the body. Digestive signs and symptoms are more common in children and can include

  • abdominal bloating
  • chronic diarrhea
  • constipation
  • gas
  • pale, foul-smelling, or fatty stool
  • stomach pain
  • nausea
  • vomiting

Being unable to absorb nutrients during the years when nutrition is critical to a child's normal growth and development can lead to other health problems, such as

  • failure to thrive in infants
  • slowed growth and short stature
  • weight loss
  • irritability or change in mood
  • delayed puberty
  • dental enamel defects of permanent teeth

Adults are less likely to have digestive signs and symptoms and may instead have one or more of the following:

  • anemia
  • bone or joint pain
  • canker sores inside the mouth
  • depression or anxiety
  • dermatitis herpetiformis, an itchy, blistering skin rash
  • fatigue, or feeling tired
  • infertility or recurrent miscarriage
  • missed menstrual periods
  • seizures
  • tingling numbness in the hands and feet
  • weak and brittle bones, or osteoporosis
  • headaches

Intestinal inflammation can cause other symptoms, such as

  • feeling tired for long periods of time
  • abdominal pain and bloating
  • ulcers
  • blockages in the intestine

Celiac disease can produce an autoimmune reaction, or a self-directed immune reaction, in which a person's immune system attacks healthy cells in the body. This reaction can spread outside of the gastrointestinal tract to affect other areas of the body, including the

  • spleen
  • skin
  • nervous system
  • bones
  • joints

Recognizing celiac disease can be difficult because some of its symptoms are similar to those of other diseases and conditions. Celiac disease can be confused with

  • irritable bowel syndrome (IBS)
  • iron-deficiency anemia caused by menstrual blood loss
  • lactose intolerance
  • inflammatory bowel disease
  • diverticulitis
  • intestinal infections
  • chronic fatigue syndrome

As a result, celiac disease has long been underdiagnosed or misdiagnosed. As health care providers become more aware of the many varied symptoms of the disease and reliable blood tests become more available, diagnosis rates are increasing, particularly for adults.