Celiac Disease
Causes, Symptoms, Diagnosis, Treatment, and Living Gluten-Free
What Is Celiac Disease?
Celiac disease is a chronic, immune-mediated disorder triggered by eating gluten, a protein found in wheat, barley, and rye. In genetically susceptible people, gluten exposure damages the small intestine’s villi, leading to malabsorption of nutrients and a wide range of gastrointestinal and non-gastrointestinal symptoms. A strict, lifelong gluten-free diet is the only effective treatment.
How Celiac Disease Works
In celiac disease, the body’s immune system overreacts to gluten (a protein in wheat, barley, and rye). An enzyme in the gut slightly changes pieces of gluten, and in people with certain genes (HLA-DQ2 or HLA-DQ8), the immune system mistakes these pieces for a threat and attacks. This attack damages the lining of the small intestine: the tiny, finger-like villi that absorb nutrients get flattened, the glands in the lining overgrow, and lots of immune cells move in. With the villi damaged, the gut can’t absorb nutrients well, leading to deficiencies and whole‑body problems like fatigue, anemia, bone weakness, and other symptoms driven by ongoing inflammation.
Who Is at Risk?
Risk is higher in people with first-degree relatives who have celiac disease and those with HLA-DQ2 or HLA-DQ8 genes. It is also associated with autoimmune conditions (type 1 diabetes, autoimmune thyroid disease), Down syndrome, Turner syndrome, Williams syndrome, selective IgA deficiency, and microscopic colitis. It can develop at any age.
Signs and Symptoms
Gastrointestinal
Chronic diarrhea Constipation
Bloating
Gas
Abdominal Pain
Nausea
Vomiting
Steatorrhea*
Weight Loss
In children
Poor weight gain
growth delay
irritability
abdominal distention
dental enamel defects
Non-GI/Systemic
Iron-deficiency anemia
fatigue
headaches
mouth ulcers
bone or joint pain
peripheral neuropathy (numbness/tingling)
dermatitis herpetiformis (itchy blistering rash)
elevated liver enzymes
infertility
recurrent miscarriage
delayed puberty
short stature in children
mood changes (anxiety, depression)
*Steatorrhea is a condition characterized by the presence of excess fat in the stool, leading to bulky, pale, and foul-smelling feces that may float. It often indicates issues with fat digestion or absorption, which can be caused by various medical conditions affecting the pancreas, liver, or intestines.
Potential Complications
Nutrient deficiencies
Iron, folate, vitamin B12, vitamin D, calcium, zinc, magnesium, copper.
Reproductive
Infertility, adverse pregnancy outcomes.
Bone health
Osteopenia/osteoporosis, fractures due to calcium and vitamin D malabsorption.
Other
Dermatitis herpetiformis, secondary lactose intolerance, hyposplenism, elevated liver enzymes, peripheral neuropathy, ataxia.
Malignancy risk
Increased risk of enteropathy-associated T-cell lymphoma (EATL) and small bowel adenocarcinoma; absolute risk is low and reduced by strict long-term adherence to a gluten-free diet.
Refractory celiac disease
Persistent villous atrophy and symptoms despite a strict gluten-free diet, requiring specialist care.
Diagnosis
Initial blood tests
tTG-IgA and total serum IgA (to detect IgA deficiency). If IgA deficient, use tTG-IgG and/or deamidated gliadin peptide (DGP) IgG. Endomysial antibody (EMA-IgA) may confirm positive results.
Endoscopy with duodenal biopsies
Confirms diagnosis by demonstrating villous atrophy and increased intraepithelial lymphocytes. Multiple biopsies are recommended.
HLA typing
Presence of HLA-DQ2 or HLA-DQ8 supports susceptibility; absence makes celiac disease very unlikely.
Special cases
In certain pediatric protocols with very high tTG-IgA levels plus EMA positivity and symptoms, a biopsy-sparing diagnosis may be considered by a specialist. If already on a gluten-free diet, a medically supervised gluten challenge may be needed.
Differential Diagnosis
Several conditions can mimic celiac disease.
Treatment Overview
The cornerstone of treatment is a strict, lifelong gluten-free diet, eliminating all sources of wheat, barley, and rye. Most people experience symptom improvement within weeks and ongoing intestinal healing over months. Persistent symptoms usually reflect hidden gluten exposure, other food intolerances, overlapping conditions, or, rarely, refractory celiac disease.
Gluten-Free Diet Basics
Completely avoid wheat (including spelt, durum, semolina, farina, farro, kamut), barley (including malt and malt extract), and rye. Oats are naturally gluten-free but frequently cross-contaminated; choose certified gluten-free oats and introduce gradually.
Naturally gluten-free foods
Fresh fruits and vegetables, legumes, plain meats, poultry, fish, eggs, dairy, nuts and seeds, and gluten-free whole grains (rice, corn, quinoa, buckwheat, millet, sorghum, amaranth, teff).
Hidden sources
Sauces and gravies, soy sauce (use tamari or gluten-free soy sauce), malt vinegar, beer (choose gluten-free beer or cider), processed meats, soups, seasoning mixes, candy, medications and supplements.
Label reading
In many countries, “gluten-free” indicates <20 ppm gluten. In the U.S., wheat is a major allergen that must be declared, but barley and rye are not; look for terms like malt, brewer’s yeast, and barley extract. When in doubt, contact manufacturers.
Preventing Cross-Contact
Small amounts of gluten can cause intestinal damage.
At home
Use separate toaster, cutting boards, wooden utensils, and condiment jars; clean surfaces thoroughly; consider dedicated gluten-free cookware.
Dining out
Ask about dedicated fryers, clean pans, separate prep areas, and ingredient lists; avoid bulk bins.
Travel
Pack safe snacks, research restaurants, and carry a card describing your dietary needs.
Nutrition and Supplementation
Nutrient deficits are common at diagnosis and may persist without careful planning.
Assess and, if needed, supplement
Iron, folate, vitamin B12, vitamin D, calcium, zinc, magnesium, copper, and fat-soluble vitamins (A, E, K) as indicated by labs.
Bone health
Ensure adequate calcium and vitamin D; consider a DEXA scan in adults at diagnosis or within the first year, then based on risk and recovery.
Fiber and microbiome
Emphasize naturally gluten-free whole foods, legumes, and pseudo-grains for fiber. Evidence for probiotics is mixed; use case-by-case.
Oats
Certified gluten-free oats can add fiber and variety; a minority may react to avenin. Introduce after initial recovery and monitor symptoms with your clinician.
Monitoring and Follow-Up
Clinical review
Symptom tracking, nutritional assessment, and adherence counseling 3-6 months after diagnosis and annually thereafter.
Serology
tTG-IgA typically declines within 6-12 months on a strict diet; persistent elevation suggests gluten exposure or another issue.
Repeat endoscopy
Consider if symptoms or serology do not improve, in refractory cases, or per specialist guidance.
Vaccinations
Stay current with routine vaccines. Discuss pneumococcal vaccination if hyposplenism is present.
Associated conditions
Periodically screen for thyroid dysfunction, type 1 diabetes complications, and other autoimmune conditions as indicated.
Special Populations
Children
Focus on growth, development, and school/daycare meal planning. Coordinate care with a pediatric gastroenterologist and dietitian. Many children recover growth once on a gluten-free diet.
Pregnancy
Well-managed celiac disease supports healthy pregnancy outcomes. Optimize nutritional status (folate, iron, B12, vitamin D) before conception; maintain strict gluten avoidance.
Older adults
Higher risk of bone disease and nutrient deficiencies. Evaluate bone density and ensure adequate protein, calcium, and vitamin D.
Associated Conditions and Screening
Screen first-degree relatives (parents, siblings, children) with serology, even if asymptomatic, because risk is higher than average.
People with type 1 diabetes, autoimmune thyroid disease, Down syndrome, Turner syndrome, selective IgA deficiency, or persistent iron-deficiency anemia should also be considered for testing.
Living Well Gluten-Free
A gluten-free life is entirely achievable with planning and support. Work with a registered dietitian experienced in celiac disease, build a repertoire of safe recipes, and leverage community resources. Over time, label reading and dining out become easier, and most people regain energy and overall health.
When to Seek Medical Care
Contact your healthcare provider if you have:
Seek urgent care for signs of severe dehydration, acute abdominal pain, or suspected intestinal obstruction.
Frequently Asked Questions
Is non-celiac gluten sensitivity the same as celiac disease?
No. NCGS does not cause the intestinal damage seen in celiac disease and is a diagnosis of exclusion.
Can I ever reintroduce gluten?
No. Celiac disease requires lifelong gluten avoidance.
Are “gluten-removed” beers safe?
No. Choose beers brewed from gluten-free grains.
Do medications and supplements contain gluten?
Many are gluten-free, but excipients can vary. Verify with the manufacturer or pharmacist.
Do I need special cookware?
Not necessarily, but separate or well-cleaned equipment reduces cross-contact risk.
