Celiac Disease: How Gluten Damages Your Gut, and How a Gluten-Free Diet Can Heal It
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
Celiac disease is an autoimmune condition in which the immune system reacts to gluten and damages the villi of the small intestine that absorb nutrients. [1] This can cause diarrhea, fatigue, weight loss, bloating and anemia, or sometimes no digestive symptoms. [1] [3] There is no cure; a strict, lifelong gluten-free diet lets the intestine heal over months to years. [1] [2]
What the research says
About 1 in 120 people worldwide has biopsy-confirmed celiac disease, and many have no symptoms. A systematic review and meta-analysis of 87 articles (394,274 participants) found a global seroprevalence of 1.5% and biopsy-confirmed prevalence of 0.8%. Prevalence was about 50% higher in females and nearly doubled in children, and 41.4% of biopsy-confirmed patients were asymptomatic (PubMed: Karimzadhagh et al., Gastroenterology, 2026) [3].
Iron deficiency anemia and diarrhea are the commonest presentations in a regional meta-analysis. Across 14 studies of Pakistani patients (1,578 people), iron deficiency anemia (65.9%) and diarrhea (64.6%) were most frequent, and villous atrophy was found in 96.9% of biopsies. The authors noted frequent delayed diagnosis and overlap with other autoimmune diseases; results come from one region (PubMed: Khan et al., Euroasian J Hepatogastroenterol, 2026) [4].
Cancer risk is considered relatively low, especially on a strict gluten-free diet. A 2026 review of malignancy in adult celiac disease concluded that the risk of cancers such as T-cell lymphoma and small intestinal adenocarcinoma is relatively low, particularly with strict gluten-free eating, and proposed individualized endoscopic surveillance. It is a narrative review rather than a pooled analysis (PubMed: Bures et al., Front Oncol, 2026) [5].
What Is Celiac Disease?
Celiac disease is an autoimmune condition where the immune system reacts to gluten, sometimes causing damage to the small intestine. [1] Gluten is a protein found in foods containing wheat, barley or rye. [1]
Your small intestine is lined with tiny hairlike projections called villi, which absorb sugars, fats, proteins, vitamins, minerals and other nutrients from the food you eat. [1] If you have celiac disease, eating gluten triggers an immune response in your small intestine. Over time, this reaction damages the villi and prevents them from absorbing nutrients, [1] a condition called malabsorption.
The intestinal damage often causes symptoms such as diarrhea, fatigue, weight loss, bloating or anemia, and it can lead to serious complications if it is not managed. [1] In children, malabsorption can affect growth and development in addition to causing digestive symptoms. [1]
There is no definite cure for celiac disease, but for most people a strict gluten-free diet helps manage symptoms and helps the intestines heal. [1] Many people with celiac disease do not know they have it. If you suspect celiac disease, get tested before cutting out gluten, otherwise the test results may appear normal. [2]
What are the symptoms of celiac disease?
The symptoms of celiac disease vary greatly and may differ between children and adults. Digestive symptoms in adults include diarrhea, fatigue, weight loss, bloating and gas, belly pain, nausea and vomiting, and constipation. [1] However, more than half of adults with celiac disease have symptoms that are not related to the digestive system, [1] which is one reason the condition so often goes undiagnosed.
Symptom Type | Symptoms |
Digestive (adults) | Diarrhea; fatigue; weight loss; bloating and gas; belly pain; nausea and vomiting; constipation |
Anemia and bone | Anemia (usually iron deficiency); loss of bone density (osteoporosis) or softened bones (osteomalacia) |
Skin and mouth | Itchy, blistery skin rash (dermatitis herpetiformis); mouth ulcers |
Brain and nerves | Headaches and fatigue; numbness and tingling in the hands and feet; balance problems; cognitive impairment |
Other | Joint pain; reduced spleen function (hyposplenism); elevated liver enzymes |
Symptoms in Children
Children with celiac disease are more likely than adults to have digestive problems, including nausea and vomiting, chronic diarrhea, a swollen belly, constipation, gas, and pale, foul-smelling stools. [1]
Possible Effect in Children | What It Looks Like |
Growth | Failure to thrive (infants); short stature; weight loss; delayed puberty |
Digestive | Swollen belly; chronic diarrhea; pale, foul-smelling stools; gas |
Blood and teeth | Anemia; damage to tooth enamel |
Behavior and nerves | Irritability; ADHD; learning disabilities; headaches; lack of muscle coordination; seizures |
Dermatitis Herpetiformis
Gluten intolerance can cause an itchy, blistery skin disease called dermatitis herpetiformis. [1] The rash usually appears on the elbows, knees, torso, scalp or buttocks. [1] Like celiac disease, it is often associated with changes to the lining of the small intestine, but it might not cause digestive symptoms. [1] Healthcare professionals treat it with a gluten-free diet or medicine, or both. [1]
When should you see a doctor about celiac disease?
Consult your healthcare team if you have diarrhea or digestive discomfort that lasts more than two weeks. [1] Consult your child’s healthcare team if your child is pale, irritable, failing to grow, has a potbelly, or has foul-smelling, bulky stools. [1]
Consult your healthcare team before trying a gluten-free diet. If you stop or even reduce the amount of gluten you eat before you are tested for celiac disease, you can change the test results. [1] [2]
Celiac disease tends to run in families. [1] If someone in your family has the condition, ask whether you should be tested. Also ask about testing if you or a family member has a risk factor such as type 1 diabetes. [1]
How does gluten cause damage in celiac disease?
A person’s genes, combined with eating foods with gluten and other factors, can contribute to celiac disease. [1] The precise cause is not known. [1] Infant-feeding practices, gastrointestinal infections and gut bacteria may contribute, but these have not been proved. [1] Celiac disease sometimes becomes active after surgery, pregnancy, childbirth, a viral infection or severe emotional stress. [1]
When the immune system overreacts to gluten in food, the reaction damages the villi that line the small intestine. [1] If your villi are damaged, you cannot get enough nutrients, no matter how much you eat. [1]
What are the risk factors for celiac disease?
Celiac disease tends to be more common in people with certain family or medical backgrounds.
Risk Factor | Why It Matters |
A family member with celiac disease or dermatitis herpetiformis | The condition tends to run in families |
Type 1 diabetes | A known autoimmune-associated risk factor |
Down syndrome, Williams syndrome or Turner syndrome | Genetic conditions linked to higher risk |
Autoimmune thyroid disease | Autoimmune conditions cluster together |
Microscopic colitis | Another intestinal condition associated with celiac disease |
Addison’s disease | An associated autoimmune condition |
What complications can celiac disease cause?
Celiac disease that is not treated can lead to serious problems. [1] The common thread is damage to the small intestine’s ability to absorb what your body needs.
Complication | What Happens |
Malnutrition | Not enough nutrients are absorbed, leading to anemia and weight loss; in children, slow growth and short stature |
Bone weakening | Calcium and vitamin D malabsorption: osteomalacia or rickets in children, osteopenia or osteoporosis in adults |
Infertility and miscarriage | Poor absorption of calcium and vitamin D can contribute to reproductive issues |
Lactose intolerance | Intestinal damage causes belly pain and diarrhea with dairy; it may improve once the intestine heals |
Cancer | People who do not maintain a gluten-free diet have a greater risk of intestinal lymphoma and small bowel cancer |
Nervous system conditions | Seizures; peripheral neuropathy (nerve disease of the hands and feet) |
Nonresponsive Celiac Disease
Some people with celiac disease do not respond to what they consider a gluten-free diet. [1] This is often due to contamination of the diet with gluten, and working with a dietitian can help you learn to avoid all gluten. [1] Other explanations include bacterial overgrowth in the small intestine, microscopic colitis, poor pancreas function (pancreatic insufficiency), irritable bowel syndrome, or difficulty digesting lactose, table sugar (sucrose) or fructose. [1] In rare cases it may be truly refractory celiac disease. [1]
Refractory Celiac Disease
In rare instances, the intestinal injury does not respond to a strict gluten-free diet. [1] If you still have symptoms after following a gluten-free diet for 6 months to 1 year, talk to your healthcare team about further testing. [1]
How is celiac disease diagnosed?
Celiac disease often goes unnoticed, so diagnosis usually starts with blood tests, followed by further testing if the results point to the condition. Two blood tests can help diagnose it: [2]
Be tested before trying a gluten-free diet. [2] Eliminating gluten might make blood test results appear in the standard range. [2] If the blood tests point to celiac disease, one of these tests will likely follow: [2]
Test | What It Does |
Endoscopy | A tiny camera on a flexible tube examines the upper digestive system, and a tissue sample (biopsy) is checked for damage to the villi |
Capsule endoscopy | A vitamin-sized wireless camera takes thousands of pictures of the small intestine; used when the whole or end of the small intestine needs to be examined |
Skin biopsy | If dermatitis herpetiformis is suspected, a small skin sample is examined under a microscope |
If you are diagnosed, additional testing may check your nutritional status, including vitamins A, B-12, D and E, mineral levels, hemoglobin and liver enzymes, and a bone density scan may check your bone health. [2]
How is celiac disease treated with a gluten-free diet?
A strict, lifelong gluten-free diet is the only way to manage celiac disease. [2] Besides wheat, foods that contain gluten include barley, bulgur, durum, farina, graham flour, malt, rye, semolina, spelt (a form of wheat) and triticale. [2] A dietitian who works with people with celiac disease can help you plan a healthy gluten-free diet. [2] Even trace amounts of gluten can be damaging, even if they do not cause symptoms. [2]
Gluten can be hidden in foods, medicines and nonfood products: [2]
Hidden Gluten Source | Examples |
Food ingredients | Modified food starch, preservatives, food stabilizers |
Medicines | Prescription and over-the-counter medicines |
Supplements | Vitamin and mineral supplements; herbal and nutritional supplements |
Personal care | Lipstick products; toothpaste and mouthwash; certain makeup products |
Other products | Communion wafers; envelope and stamp glue; play dough |
Removing gluten from your diet will typically reduce inflammation in your small intestine, so you feel better and eventually heal. [2] Children tend to heal more quickly than adults. [2]
Vitamin and Mineral Supplements
If your anemia or nutritional deficiencies are severe, supplements may be recommended, including copper, folic acid, iron, vitamin B-12, vitamin D, vitamin K and zinc. [2] They are usually taken as pills, and if your digestive tract has trouble absorbing vitamins, you might be able to get them by injection. [2]
Medicines for Severe Cases
If your small intestine is severely damaged or you have refractory celiac disease, steroids may be recommended to control inflammation and ease severe symptoms while the intestine heals. [2] Other medicines, such as azathioprine or budesonide, might be used. [2] For dermatitis herpetiformis, dapsone may be recommended in addition to a gluten-free diet, with regular blood tests to check for side effects. [2] Refractory celiac disease can be quite serious and there is currently no proven treatment, so you may want to seek care at a specialized center. [2]
Follow-Up Care
Medical follow-up at regular intervals can confirm that your symptoms have responded to a gluten-free diet, and your team may monitor you with blood tests and regular checks of nutritional markers. [2] For most people, a gluten-free diet allows the small intestine to heal: usually 3 to 6 months for children, and possibly several years for adults. [2] If symptoms continue or recur, you might need an endoscopy with biopsies to find out whether your intestine has healed. [2]
How can you eat safely without gluten with celiac disease?
If you have been diagnosed, you will need to avoid all foods that contain gluten. [2] Ask your healthcare team for a referral to a dietitian who can help you plan a healthy gluten-free diet. [2]
Read labels. Avoid packaged foods unless they are labeled gluten-free or have no gluten-containing ingredients, including emulsifiers and stabilizers that can contain gluten. [2] Besides cereals, pastas and baked goods, packaged foods that can contain gluten include beers, lagers, ales and malt vinegars; candies; gravies; imitation meats or seafood; processed luncheon meats; rice mixes; salad dressings and sauces (including soy sauce); seasoned snack foods such as tortilla and potato chips; seitan; self-basting poultry; and soups. [2]
Oats. Pure oats are not harmful for most people with celiac disease, but oats can be contaminated by wheat during growing and processing. [2] Ask your healthcare team whether you can try small amounts of pure oat products. [2]
Foods you can eat. Many basic foods are allowed: eggs; fresh meats, fish and poultry that are not breaded, batter-coated or marinated; fruits; lentils; most dairy products (unless they make your symptoms worse); nuts; potatoes; vegetables; and wine and distilled liquors, ciders and spirits. [2] Allowed grains and starches include amaranth, buckwheat, corn, cornmeal, gluten-free flours (rice, soy, corn, potato, bean), pure corn tortillas, quinoa, rice, tapioca and wild rice. [2]
How can people cope with celiac disease and find support?
Following a completely gluten-free diet for celiac disease can be a challenge, but education, your provider's guidance and support groups can help. [2] These steps can help you feel more in control:
Get educated and teach family and friends. They can support your efforts. [2]
Follow your healthcare professional’s recommendations. It is critical to eliminate all gluten from your diet. [2]
Find a support group. Organizations such as the Celiac Disease Foundation, Gluten Intolerance Group, the National Celiac Association and Beyond Celiac can connect you with others who share your challenges. [2]
How should you prepare for a celiac disease appointment?
You might be referred to a gastroenterologist, a doctor who treats digestive diseases. [2] Until your appointment, continue eating your usual diet, because cutting gluten before testing can change the results. [2] Make a list of your symptoms (including when they started and whether they have changed), key personal information (major stresses, recent life changes, and whether anyone in your family has celiac disease or another autoimmune condition), all medicines, vitamins and supplements with doses, and questions to ask. [2] Useful questions include: What is the most likely cause of my symptoms? Is my condition temporary or long term? What tests do I need? What treatments can help? Do I need to follow a gluten-free diet? [2]
Your doctor may ask how severe your symptoms are, whether they have been continuous or occasional, what improves or worsens them, what medicines and pain relievers you take, and whether you have been diagnosed with anemia or osteoporosis. [2]
Conclusion: Healing Starts the Day You Remove Gluten
Celiac disease is not a simple food sensitivity. It is an autoimmune condition in which your own immune system attacks the small intestine every time you eat gluten. [1] Over time, that damage blocks nutrient absorption and can affect your bones, blood, skin, nerves and growth. [1]
A strict, lifelong gluten-free diet is a highly effective treatment. It quiets the inflammation, restores the intestine’s ability to absorb nutrients and lets the villi heal, in months for children and over several years for most adults. [2] The hardest parts are hidden gluten and the temptation to relax the diet once symptoms fade, but even trace amounts can keep doing damage without causing symptoms. Label reading, a dietitian’s guidance and regular follow-up testing turn a gluten-free diet into lasting protection.
Next steps: If you have digestive discomfort lasting more than two weeks, or unexplained anemia, fatigue or bone loss, ask your healthcare team about celiac testing before changing your diet.
Frequently Asked Questions
1. What is celiac disease?
An autoimmune condition in which eating gluten (a protein in wheat, barley and rye) damages the villi of the small intestine and blocks nutrient absorption. There is no cure, but a strict gluten-free diet manages symptoms and lets the intestine heal.
2. What are the symptoms of celiac disease?
Adults may have diarrhea, fatigue, weight loss, bloating, belly pain, nausea or constipation. More than half also have non-digestive symptoms such as anemia, bone loss, an itchy blistery rash, headaches, numbness and tingling, or joint pain.
3. What is the difference between celiac disease and gluten sensitivity?
Celiac disease is autoimmune and damages the small intestine’s villi, causing malabsorption. Gluten sensitivity causes uncomfortable symptoms after eating gluten but does not damage the intestine.
4. Can celiac disease go away?
No. There is no cure, but a strict, lifelong gluten-free diet lets the intestine heal: usually 3 to 6 months in children, and possibly several years in adults.
5. Do I need to avoid gluten if I have no symptoms?
Yes. Even trace amounts of gluten can keep damaging the intestine without causing symptoms, so all gluten must be avoided for life.
6. What tests diagnose celiac disease?
Blood tests (antibody serology; HLA-DQ2/DQ8 genetic testing can rule it out) come first, followed by an endoscopy with a small-intestine biopsy if results point to celiac disease. Testing must happen while you still eat gluten.
7. Why can’t I start a gluten-free diet before testing?
Cutting or reducing gluten before testing can make blood test results look normal and hide the diagnosis. Keep eating gluten until testing is complete.
8. What foods contain gluten that I should avoid?
Wheat, barley, rye, bulgur, durum, farina, graham flour, malt, semolina, spelt and triticale. Hidden sources include soy sauce, gravies, processed meats, beer, some medicines and supplements, and even lipstick and toothpaste.
9. What foods are safe on a gluten-free diet?
Eggs, fresh meat and fish, fruits, vegetables, lentils, nuts, potatoes, most dairy, rice, quinoa, buckwheat, corn and gluten-free flours. Pure oats are safe for most people if not contaminated by wheat.
10. What are the complications of untreated celiac disease?
Malnutrition, anemia, bone loss, infertility and miscarriage, lactose intolerance, a higher risk of intestinal lymphoma and small bowel cancer, and nervous system conditions such as seizures and peripheral neuropathy.
Further Reading
Related Reading
Learn more in our guide to Antibody Test (Serology): What It Detects, Uses and What Results Mean.
Capsule Endoscopy: How a Swallowed Camera Pill Checks Your Small Intestine, Prep and Results explains the swallowed-camera test used to look inside the small intestine.
Learn more in our guide to Lipase Blood Test: Normal Range, High and Low Levels and What They Mean.
tTG-IgA Test for Celiac Disease: Normal Ranges, What Results Mean and Next Steps explains the main blood test used to diagnose celiac disease.
References
Mayo Clinic Staff. Celiac disease - Symptoms and causes. Mayo Clinic. Mar. 4, 2026. https://www.mayoclinic.org/diseases-conditions/celiac-disease/symptoms-causes/syc-20352220
Mayo Clinic Staff. Celiac disease - Diagnosis and treatment. Mayo Clinic. Mar. 4, 2026. https://www.mayoclinic.org/diseases-conditions/celiac-disease/diagnosis-treatment/drc-20352225
Karimzadhagh S, Abbaspour E, Shamsi P, et al. Global prevalence of celiac disease and clinical characteristics in the general population: a systematic review and meta-analysis. Gastroenterology. 2026 (published online Aug. 18, 2026). PMID 42612883. https://doi.org/10.1053/j.gastro.2026.07.028
Khan RT, Luck NH, Kumar SK, et al. Demographic profile and clinical presentation of celiac disease in the Pakistani population: a systematic review and meta-analysis. Euroasian J Hepatogastroenterol. 2026;16(1):12-19. PMID 42798675. https://doi.org/10.5005/jp-journals-10018-1505
Bures J, Kamaradova K, Rezacova V, et al. Risk of malignancy and surveillance of premalignant gastrointestinal lesions in adult celiac disease. Front Oncol. 2026;16:1876345. PMID 42757030. https://doi.org/10.3389/fonc.2026.1876345
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read here.
Comments