What is celiac disease?
Celiac disease is a digestive disease that damages the small intestine and
interferes with absorption of nutrients from food. People who have celiac
disease cannot tolerate gluten, a protein in wheat, rye, and barley. Gluten is
found mainly in foods but may also be found in everyday products such as
medicines, vitamins, and lip balms.

The small intestine is shaded above.
When people with celiac disease eat foods or use products containing gluten,
their immune system responds by damaging or destroying villi—the tiny,
fingerlike protrusions lining the small intestine. Villi normally allow
nutrients from food to be absorbed through the walls of the small intestine into
the bloodstream. Without healthy villi, a person becomes malnourished, no matter
how much food one eats.

Villi on the lining of the small intestine help absorb
nutrients.
Celiac disease is both a disease of malabsorption—meaning nutrients are not
absorbed properly—and an abnormal immune reaction to gluten. Celiac disease is
also known as celiac sprue, nontropical sprue, and gluten-sensitive enteropathy.
Celiac disease is genetic, meaning it runs in families. Sometimes the disease is
triggered—or becomes active for the first time—after surgery, pregnancy,
childbirth, viral infection, or severe emotional stress.
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What are the
symptoms of celiac disease?
Symptoms of celiac disease vary from person to person. Symptoms may occur in the
digestive system or in other parts of the body. Digestive symptoms are more
common in infants and young children and may include
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abdominal bloating and pain
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chronic diarrhea
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vomiting
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constipation
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pale, foul-smelling, or fatty stool
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weight loss
Irritability is another common symptom in children. Malabsorption of nutrients
during the years when nutrition is critical to a child’s normal growth and
development can result in other problems such as failure to thrive in infants,
delayed growth and short stature, delayed puberty, and dental enamel defects of
the permanent teeth.
Adults are less likely to have digestive symptoms and may instead have one or
more of the following:
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unexplained iron-deficiency anemia
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fatigue
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bone or joint pain
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arthritis
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bone loss or osteoporosis
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depression or anxiety
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tingling numbness in the hands and feet
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seizures
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missed menstrual periods
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infertility or recurrent miscarriage
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canker sores inside the mouth
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an itchy skin rash called dermatitis herpetiformis
People with celiac disease may have no symptoms but can still develop
complications of the disease over time. Long-term complications include
malnutrition—which can lead to anemia, osteoporosis, and miscarriage, among
other problems—liver diseases, and cancers of the intestine.
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Why are celiac
disease symptoms so varied?
Researchers are studying the reasons celiac disease affects people differently.
The length of time a person was breastfed, the age a person started eating
gluten-containing foods, and the amount of gluten-containing foods one eats are
three factors thought to play a role in when and how celiac disease appears.
Some studies have shown, for example, that the longer a person was breastfed,
the later the symptoms of celiac disease appear.
Symptoms also vary depending on a person’s age and the degree of damage to the
small intestine. Many adults have the disease for a decade or more before they
are diagnosed. The longer a person goes undiagnosed and untreated, the greater
the chance of developing long-term complications.
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What other
health problems do people with celiac disease have?
People with celiac disease tend to have other diseases in which the immune
system attacks the body’s healthy cells and tissues. The connection between
celiac disease and these diseases may be genetic. They include
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type 1 diabetes
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autoimmune thyroid disease
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autoimmune liver disease
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rheumatoid arthritis
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Addison’s disease, a condition in which the glands that
produce critical hormones are damaged
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Sjögren’s syndrome, a condition in which the glands that
produce tears and saliva are destroyed
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How common is
celiac disease?
Celiac disease affects people in all parts of the world. Originally thought to
be a rare childhood syndrome, celiac disease is now known to be a common genetic
disorder. More than 2 million people in the United States have the disease, or
about 1 in 133 people.1
Among people who have a first-degree relative—a parent, sibling, or
child—diagnosed with celiac disease, as many as 1 in 22 people may have the
disease.2
Celiac disease is also more common among people with other genetic disorders
including Down syndrome and Turner syndrome, a condition that affects girls’
development.
1Fasano A, Berti I, Gerarduzzi T, et al. Prevalence of celiac disease
in at-risk and not-at-risk groups in the United States. Archives of Internal
Medicine. 2003;163(3):268–292.
2Ibid.
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How is celiac disease diagnosed?
Recognizing celiac disease can be difficult because some of its symptoms are
similar to those of other diseases. Celiac disease can be confused with
irritable bowel syndrome, iron-deficiency anemia caused by menstrual blood loss,
inflammatory bowel disease, diverticulitis, intestinal infections, and chronic
fatigue syndrome. As a result, celiac disease has long been underdiagnosed or
misdiagnosed. As doctors become more aware of the many varied symptoms of the
disease and reliable blood tests become more available, diagnosis rates are
increasing.
Blood Tests
People with celiac disease have higher than normal levels of certain
autoantibodies—proteins that react against the body’s own cells or tissues—in
their blood. To diagnose celiac disease, doctors will test blood for high levels
of anti-tissue transglutaminase antibodies (tTGA) or anti-endomysium antibodies
(EMA). If test results are negative but celiac disease is still suspected,
additional blood tests may be needed.
Before being tested, one should continue to eat a diet that includes foods with
gluten, such as breads and pastas. If a person stops eating foods with gluten
before being tested, the results may be negative for celiac disease even if the
disease is present.
Intestinal
Biopsy
If blood tests and symptoms suggest celiac disease, a biopsy of the small
intestine is performed to confirm the diagnosis. During the biopsy, the doctor
removes tiny pieces of tissue from the small intestine to check for damage to
the villi. To obtain the tissue sample, the doctor eases a long, thin tube
called an endoscope through the patient’s mouth and stomach into the small
intestine. The doctor then takes the samples using instruments passed through
the endoscope.
Dermatitis
Herpetiformis
Dermatitis herpetiformis (DH) is an intensely itchy, blistering skin rash that
affects 15 to 25 percent of people with celiac disease.3
The rash usually occurs on the elbows, knees, and buttocks. Most people with DH
have no digestive symptoms of celiac disease.
DH is diagnosed through blood tests and a skin biopsy. If the antibody tests are
positive and the skin biopsy has the typical findings of DH, patients do not
need to have an intestinal biopsy. Both the skin disease and the intestinal
disease respond to a gluten-free diet and recur if gluten is added back into the
diet. The rash symptoms can be controlled with antibiotics such as dapsone.
Because dapsone does not treat the intestinal condition, people with DH must
maintain a gluten-free diet.
Screening
Screening for celiac disease means testing for the presence of autoantibodies in
the blood in people without symptoms. Americans are not routinely screened for
celiac disease. However, because celiac disease is hereditary, family members of
a person with the disease may wish to be tested. Four to 12 percent of an
affected person’s first-degree relatives will also have the disease.4
3Rodrigo L. Celiac disease. World Journal of Gastroenterology.
2006;12(41):6585–6593.
4Ibid.
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How is celiac disease treated?
The only treatment for celiac disease is a gluten-free diet. Doctors may ask a
newly diagnosed person to work with a dietitian on a gluten-free diet plan. A
dietitian is a health care professional who specializes in food and nutrition.
Someone with celiac disease can learn from a dietitian how to read ingredient
lists and identify foods that contain gluten in order to make informed decisions
at the grocery store and when eating out.
For most people, following this diet will stop symptoms, heal existing
intestinal damage, and prevent further damage. Improvement begins within days of
starting the diet. The small intestine usually heals in 3 to 6 months in
children but may take several years in adults. A healed intestine means a person
now has villi that can absorb nutrients from food into the bloodstream.
To stay well, people with celiac disease must avoid gluten for the rest of their
lives. Eating even a small amount of gluten can damage the small intestine. The
damage will occur in anyone with the disease, including people without
noticeable symptoms. Depending on a person’s age at diagnosis, some problems
will not improve, such as short stature and dental enamel defects.
Some people with celiac disease show no improvement on the gluten-free diet. The
most common reason for poor response to the diet is that small amounts of gluten
are still being consumed. Hidden sources of gluten include additives such as
modified food starch, preservatives, and stabilizers made with wheat. And
because many corn and rice products are produced in factories that also
manufacture wheat products, they can be contaminated with wheat gluten.
Rarely, the intestinal injury will continue despite a strictly gluten-free diet.
People with this condition, known as refractory celiac disease, have severely
damaged intestines that cannot heal. Because their intestines are not absorbing
enough nutrients, they may need to receive nutrients directly into their
bloodstream through a vein, or intravenously. Researchers are evaluating drug
treatments for refractory celiac disease.
The
Gluten-free Diet
A gluten-free diet means not eating foods that contain wheat, rye, and barley.
The foods and products made from these grains should also be avoided. In other
words, a person with celiac disease should not eat most grain, pasta, cereal,
and many processed foods.
Despite these restrictions, people with celiac disease can eat a well-balanced
diet with a variety of foods. They can use potato, rice, soy, amaranth, quinoa,
buckwheat, or bean flour instead of wheat flour. They can buy gluten-free bread,
pasta, and other products from stores that carry organic foods, or order
products from special food companies. Gluten-free products are increasingly
available from mainstream stores.
“Plain” meat, fish, rice, fruits, and vegetables do not contain gluten, so
people with celiac disease can freely eat these foods. In the past, people with
celiac disease were advised not to eat oats. New evidence suggests that most
people can safely eat small amounts of oats, as long as the oats are not
contaminated with wheat gluten during processing. People with celiac disease
should work closely with their health care team when deciding whether to include
oats in their diet. Examples of other foods that are safe to eat and those that
are not are provided in the table.
The gluten-free diet requires a completely new approach to eating. Newly
diagnosed people and their families may find support groups helpful as they
learn to adjust to a new way of life. People with celiac disease must be
cautious about what they buy for lunch at school or work, what they purchase at
the grocery store, what they eat at restaurants or parties, and what they grab
for a snack. Eating out can be a challenge. When in doubt about a menu item, a
person with celiac disease should ask the waiter or chef about ingredients and
preparation or if a gluten-free menu is available.
Gluten is also used in some medications. People with celiac disease should ask a
pharmacist if prescribed medications contain wheat. Because gluten is sometimes
used as an additive in unexpected products—such as lipstick and play
dough—reading product labels is important. If the ingredients are not listed on
the label, the manufacturer should provide a list upon request. With practice,
screening for gluten becomes second nature.
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