What is celiac disease? The autoimmune disorder 2.5 million Americans don’t know they have

• Celiac disease is an autoimmune disorder where eating gluten causes damage to the small intestine.
• Celiac disease symptoms may include gas, bloating, a rash, constipation, and fatigue.
• Once celiac disease is diagnosed with a blood test and endoscopy, you must eat a gluten-free diet.
• Visit Insider's Health Reference library for more advice.

About 1% of people worldwide are estimated to have celiac disease, a chronic condition that causes an adverse reaction to gluten. If left untreated, celiac disease can cause serious damage to the small intestine and result in long-term health consequences, like nutritional deficiencies.

For children in particular, malnutrition caused by celiac disease could lead to stunted growth and development, in addition to negative symptoms including digestive issues.

That's why recognizing the symptoms and properly treating the condition are crucial, especially since an estimated 2.5 million Americans are undiagnosed.

What is celiac disease?

Celiac disease is an autoimmune disorder in which eating gluten causes the immune system to attack the lining of the small intestine. This reaction damages the lining over time and prevents the proper absorption of nutrients, says Badr Al Bawardy, MD, a gastroenterologist at Yale Medicine.

Gluten is a protein found in certain grains including wheat, rye, and barley. For most people, eating gluten will not cause any side effects.

Celiac disease is hereditary, meaning if you have a blood relative with the condition, you could have an increased risk of developing it. However, not all cases are triggered by genetic history.

Celiac disease is different from gluten intolerance since, if left untreated, it can lead to serious health complications, including osteoporosis, infertility, and in rare cases, intestinal cancer, says Al Bawardy. Meanwhile, a gluten intolerance will only cause short-term discomfort, not long-lasting problems.

How is celiac disease diagnosed?

If you suspect you have celiac disease, it's imperative you reach out to a gastroenterologist for a diagnosis due to the health risks, says Jill Deutsch, MD, a gastroenterologist at Yale Medicine.

According to Deutsch, your healthcare provider may perform two tests to diagnose the condition:

• Blood test, which checks for gluten antibodies. However, you may get a false negative if you are on a gluten-free diet.
• Upper endoscopy, which checks for small intestine damage by inserting a tube through the mouth and down the throat to take a small piece of tissue for a biopsy. This test is typically performed to confirm the diagnosis if your blood work indicates you may have celiac disease.

If you test negative for celiac disease, your doctor may perform a wheat allergy test. If those results are also negative, you may have a gluten intolerance, says Al Bawardy.

What causes celiac disease?

The exact cause of celiac disease is unknown, however, the following factors increase your risk of developing the condition:

• Genes: You are more likely to develop celiac disease if a parent or sibling has it.
• Diet: According to a large 2019 study of newborns genetically predisposed to celiac disease and type 1 diabetes, those who consumed more gluten until the age of five were more likely to develop the condition.
• Infections: Having a higher number of infections in childhood or certain gastrointestinal conditions can increase your risk of developing celiac disease.
• Other conditions like Down syndrome, Turner syndrome, and type 1 diabetes increase the risk of celiac disease.

Celiac disease treatment and diet

While celiac disease cannot be cured, it can be managed through dietary approaches.

"Currently, there are no medications available to treat celiac disease. A life-long gluten-free diet is currently the only treatment," says Al Bawardy.

If you're on a gluten-free diet, here are some of the foods you can and can't eat:

Once you start a gluten-free diet, you can expect to feel better within four to six weeks, says Deutsch.

Another part of treating celiac disease is asking your healthcare provider about getting tested for vitamin and mineral deficiencies. That's because celiac disease disrupts the absorption of nutrients, increasing the risk of deficiencies, says Al Bawardy. Depending on the results, you may have to take certain supplements.

Insider's takeaway

Celiac disease is a chronic autoimmune disorder where eating gluten causes damage to the small intestine. This can cause symptoms like gas, bloating, and fatigue, and if left untreated may lead to osteoporosis or stunted growth in children.

If you suspect you have celiac disease, see a gastroenterologist immediately to get a diagnosis.

If you do have celiac disease, the only treatment is a strict gluten-free diet. Deutsch recommends working with a registered dietitian since gluten is a common ingredient hidden in many foods, medications, and even lipsticks.

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