Celiac Disease and Gluten-Related Symptoms

What celiac disease is

Celiac disease is a chronic digestive and immune disorder that damages the small intestine. It is triggered by eating foods that contain gluten, a protein found naturally in wheat, barley and rye. [1] Experts estimate that about 2 million people in the US, and about 1 percent of people worldwide, have celiac disease, and many have not been diagnosed. [1]

Celiac disease can occur only in people with certain genes, and eating gluten triggers the abnormal immune response behind it. [1][2] Having those genes alone does not mean you have celiac disease. [3]

Symptoms are varied and overlap with other conditions

Symptoms vary widely and may come and go. Digestive symptoms, such as bloating, chronic diarrhea, constipation and gas, are more common in children than adults. [2] Some people have symptoms in other parts of the body, such as fatigue, joint or bone pain, depression or anxiety, headaches, or an itchy, blistering skin rash called dermatitis herpetiformis. [2] Some people have no symptoms but can still develop complications over time if they are not treated. [2]

Because many of these symptoms look like irritable bowel syndrome or lactose intolerance, celiac disease is not diagnosed from symptoms alone. [3] Long-term complications can include osteoporosis or bone softening, anemia and malnutrition. [1] See osteoporosis and bone health.

Test before you cut out gluten

Doctors typically diagnose celiac disease with blood tests (which look for certain antibodies) and biopsies of the small intestine taken during an upper endoscopy. [3] They do not recommend starting a gluten-free diet before diagnostic testing, because it can affect test results. [3] The American College of Gastroenterology suggests blood testing for celiac disease in people with IBS and diarrhea symptoms. [4]

If you start avoiding gluten on your own, your diet may not provide enough fiber, iron and calcium, and some packaged gluten-free foods may be higher in fat and sugar. [5] Talk with a doctor about testing before changing your diet.

Established care

The treatment is a gluten-free diet for life. It can relieve symptoms and heal intestinal damage, and symptoms typically improve and may go away after starting it. [5][2] A doctor and a registered dietitian can help you plan a healthy, balanced gluten-free diet. [5]

Practical points from NIDDK:

• Many foods are naturally gluten-free, such as meat, fish, fruits, vegetables, rice and potatoes without additives. [5]


• Gluten can be hidden in processed foods through additives made from gluten-containing grains, and cross-contact (gluten touching gluten-free food) can make food unsafe. [5]


• In the US, foods labeled "gluten-free" must contain less than 20 parts per million of gluten. [5]


• Research suggests most people with celiac disease can safely eat moderate amounts of oats, but only if the oats are gluten-free. Discuss with your doctor or dietitian. [5] See oats.

Gluten sensitivity without celiac disease

Some people feel unwell after eating gluten even though tests for celiac disease are negative. Some people with IBS have more symptoms after eating gluten, even without celiac disease. [6] This is often called non-celiac gluten sensitivity, but it is controversial: it lacks specific biomarkers and relies heavily on self-reported symptoms. [7] A 2025 review found that gluten-specific effects outside celiac disease largely disappeared once fermentable carbohydrates (FODMAPs) and expectation effects were controlled for, and suggested that a gluten-free diet be a time-limited trial supervised by a dietitian. [8]

Evidence labels: established recommendation = guideline or health agency recommends; mixed = studies disagree; insufficient evidence = not enough reliable research.

Check labels on supplements and medicines for gluten. See reading supplement labels and how interactions work.

When to get help

See a clinician before you try a gluten-free diet if you have long-lasting bloating, diarrhea, weight loss, anemia, or a blistering itchy rash. [3][2] Get urgent care for severe pain, repeated vomiting, blood in stool or signs of dehydration (see digestive symptoms: red flags). In the US, call 911 in an emergency.