What Is Celiac Disease? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Celiac disease is an autoimmune condition that prevents proper nutrient absorption and the digestion of gluten.

When people diagnosed with the condition are exposed to gluten — a binding protein common in grains but also in makeup products — the immune system malfunctions and attacks the walls of the small intestine, which is responsible for absorbing nutrients from food, according to the Celiac Disease Foundation. (1) People with celiac disease have a swollen and irritated small intestine, which can interfere with this absorption, leading to nutrient deficiencies.

The condition requires avoiding gluten to manage symptoms.

Signs and symptoms of celiac disease vary widely based on the individual. In fact, some people with the condition are asymptomatic. Generally speaking, though, there are some telltale signs of that you should know.

First, digestive problems can occur in anyone with celiac disease, but they may be more common in children with the disease than adults. Here are some of the digestive symptoms that may occur, per the National Institute of Diabetes and Digestive and Kidney Disease (NIDDK): (2)

• Abdominal pain, bloating, or gas
• Chronic diarrhea (may be constant, or on and off for several weeks)
• Constipation
• Pale, foul-smelling, or oily stool
• Nausea and vomiting
• Unexplained weight loss

On the flip side, celiac disease can cause problems in other parts of the body, too. And some of these symptoms are more common in adults than in children.

Nondigestive symptoms may include: (2)

• Anemia (low red blood cell count)
• Fatigue (extreme tiredness that doesn't go away with sleep)
• Infertility or miscarriages
• Missed menstrual periods
• Depression or anxiety
• Seizures
• Canker sores or ulcers inside the mouth
• Bone or joint pain
• Osteoporosis (weak, porous bones that break more easily)
• Itchy, blistery skin rashes
• Hair loss
• Tingling or numbness in hands or feet
• Headaches

A number of tests can help your doctor figure out whether you have celiac disease or another digestive condition.

Per the Mayo Clinic, your doctor may recommend: (7)

• Blood Tests Your blood sample will be checked for special proteins called antibodies. Certain antibodies tend to be elevated in people with celiac disease. Before your blood test, you should continue to eat foods containing gluten. Cutting out gluten before testing is complete could delay your diagnosis.
• Endoscopy Your doctor may ask a gastroenterologist to perform an endoscopy to confirm your diagnosis if a blood test shows you may have celiac disease. You'll swallow a small, flexible tube containing a tiny camera. Through this tube, your doctor will perform a biopsy, removing a tiny piece of tissue from the wall of your small intestine. A specialist (usually a pathologist) will view this tissue under a microscope to see whether it has been damaged by celiac disease.
• Genetic Testing Your doctor may order a genetic test to rule out a celiac disease diagnosis. Most people with celiac disease carry a certain variant of the HLA-DQ2 or -DQ8 genes. But many people without celiac disease also have these variants, so celiac disease can't be diagnosed by genetic testing alone.
• Bone Density Testing If you have celiac disease, your doctor will probably recommend a test to check for bone loss. This may not happen until you've been following a gluten-free diet for a year. This test uses a scanning machine similar to an X-ray. If the scan shows significant bone loss, you may need dietary supplements or other treatments to encourage bone growth.

Learn More About the Symptoms of Celiac Disease and How It’s Diagnosed

Adhering to a gluten-free diet is the best way to keep symptoms of celiac disease under control, according to a study published in July 2016 in the journal Nutrients. (9)

At first, the news of a celiac disease diagnosis may be tough to hear. For some, it might mean completely overhauling their diet. But working with a dietitian can help with the transition to a gluten-free diet while still eating healthy and nutritious foods. You'll be instructed how to:

• Use food and product labels to identify ingredients that contain gluten
• Understand which foods are naturally gluten-free
• Find and eliminate hidden sources of gluten from the diet
• Make healthy food choices
• Design meal plans

After starting on a gluten-free diet, individuals with celiac disease will continue to see a doctor for periodic checkups to make sure the condition is improving. Many doctors recommend a follow-up visit four to six weeks after starting on the diet, notes Coeliac UK. (10)

Are There Supplements That Are Good for People With Celiac Disease?

People with celiac disease are at risk of nutritional deficiencies because the disease can limit the small intestine's ability to absorb nutrients from food, per the Celiac Disease Foundation. (11) Your doctor can test for nutritional deficiencies with a simple blood test.

According to the Gluten Intolerance Group, people with celiac disease often have low levels of: (12)

• Calcium
• Vitamin B12
• Folate
• Vitamin A
• Vitamin E
• Vitamin D
• Vitamin K

Taking a multivitamin or nutritional supplement can help you build your levels of essential nutrients back up.

But keep in mind that some vitamins, minerals, and herbal supplements contain an ingredient called lecithin. Lecithin can be a hidden source of gluten. Talk to your doctor or pharmacist before taking any nutritional supplement to make sure it doesn't contain gluten.

RELATED: 7 Common Nutrient Deficiencies

Gluten-free diets are sometimes low in fiber, which can lead to constipation. A fiber supplement with psyllium seed husks can also help, as can fiber-rich foods, like fruits and veggies. (12)

Can Taking Medication Help Manage Celiac Disease?

A small percentage of people with celiac disease find that their symptoms don't improve, even with a strict gluten-free diet.

Symptoms may go away initially but then return, even in the absence of gluten. It's unclear why this happens. Doctors call this refractory celiac disease. If you have refractory celiac disease, your doctor may prescribe a steroid medication, such as Deltasone (prednisone). (7)

Steroids are typically taken for a short period of time to suppress the immune system and stop the body's harmful immune response.

How to Develop a Gluten-Free Diet to Control Celiac Disease

Gluten is found in many commonly loved foods, including traditional pizza crust, several types of sandwich breads, pasta, tortillas, cake, cookies, and even soy sauce. (1) But for people with celiac disease, knowing the foods and products gluten lurks in — and then avoiding them — is key for keeping symptoms controlled and preventing an attack.

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Foods to Avoid if You Have Celiac Disease

Any foods made with wheat, barley, or rye contain some amount of gluten. That means that people with celiac disease shouldn't eat most breakfast cereal, bread, pasta, and processed foods. (1)

Processed foods that may contain gluten include:

• Bouillon cubes
• Brown rice syrup
• Candy
• Chewing gum
• Chips, including seasoned tortilla and potato chips
• Cold cuts, hot dogs, salami, and sausage
• Communion wafers
• French fries
• Gravy
• Imitation fish
• Rice mixes
• Soy sauce
• Beer and malt beverages (1,13)

Soups and sauces are common sources of hidden gluten, as wheat is often used as a thickener. Pay special attention to sauces or soups that are cream based.

Gluten-Free Foods

Cutting gluten out of your diet may seem like a difficult task, but many foods are naturally gluten-free.

In general, the following food groups are naturally gluten-free:

• Fruits
• Vegetables
• Fresh cuts of meat and poultry
• Fish and seafood
• Dairy
• Beans, legumes, and nuts

Beware, though, that prepared or processed versions of any of the above foods, such as sausage or ice cream, may contain gluten.

There are many gluten-free grains and starches that you can substitute for wheat, barley, or rye products:

• Rice
• Corn
• Potato (but not potato chips)
• Tapioca
• Sorghum
• Soy
• Quinoa
• Millet
• Arrowroot
• Amaranth
• Teff
• Flax
• Chia
• Gluten-free oats
• Buckwheat
• Nut flours
• Bean flours

Tips for Dining Out on a Gluten-Free Diet

The following strategies may help you stick to your gluten-free diet when eating out:

• Choose a restaurant with gluten-free options. This means picking a place that serves naturally gluten-free foods or has a special gluten-free menu.
• Inform your waiter. Let them know you have celiac disease and may get sick if you eat anything containing gluten, including flour, bread crumbs, or soy sauce. Also ask them to inform the chef or cook. This way, you’ll have more confidence that nothing on your plate has touched gluten.
• Ask questions. Don't assume anything is gluten-free. Omelets, for instance, may have pancake batter added to the egg mixture to make them fluffier, and baked potatoes can be coated with flour to make the skins brown and crispy.

Nonfood Sources of Gluten

Some medicines and nutritional supplements, such as vitamins, contain gluten.

Ask your pharmacist if you aren't sure whether a medication, supplement, or over-the-counter (OTC) drug contains gluten. Some varieties of lip gloss, lipstick, and lip balm also contain gluten. (11,14)

Learn More About How to Go Gluten-Free to Manage Celiac Disease

Prevention of Celiac Disease

At this time, there is no proven way to prevent celiac disease.

The best way to keep symptoms of celiac disease under control is to maintain a gluten-free diet.

Regardless of what age you’re looking at, celiac disease is seriously underdiagnosed, likely because its symptoms manifest differently depending on who you are, according to an article published in January 2016 in Clinical and Translational Gastroenterology. (16) For example, some people with the disease have digestive problems, especially diarrhea, while others experience problems in other parts of the body, such as anemia, fatigue, headaches, and joint pain.

But best estimates put the prevalence of the condition around 1 in 100 people, or about 1 percent, of the U.S. population, per the Celiac Foundation. (17)

To date, there is no evidence or reports to suggest that individuals with celiac disease are at a greater risk of severe illness from COVID-19 than those without the condition.

The Celiac Disease Foundation is collecting physician and patient-reported data on people with celiac disease who have been diagnosed with COVID-19. (21) This data will help show the true impact of COVID-19 on people with celiac disease.

Additional reporting by Ashley Welch

To properly control celiac disease, you need more than just resources for recipes. By visiting websites such as UpToDate, the National Institute of Arthritis and Musculoskeletal and Skin Diseases National Resource Center, and the U.S. Food and Drug Administration (FDA), you can find the resources you need to thrive with this autoimmune condition.

Learn More About the Best Online Resources for Understanding and Controlling Celiac Disease