How to Test for Celiac Disease: FAQ Guide

Published January 20, 2025. Last updated March 6th, 2025.

This guide explains everything you need to know to get tested for celiac disease, from recognizing symptoms to understanding test methods and interpreting results.

Celiac disease is an autoimmune disorder in which the body’s immune system reacts to the protein gluten, found in wheat, barley, and rye.¹ This immune response can damage the lining of the small intestine, leading to malabsorption of nutrients.²

An estimated 2 million people in the U.S. have celiac disease, though many remain undiagnosed.³ Since symptoms can vary widely—or even be absent—understanding how to get tested for celiac disease is essential.

What Are the Symptoms of Celiac Disease, and Who’s at Risk?

The symptoms of celiac disease vary from person to person. Some individuals experience severe digestive issues, while others may have symptoms that aren’t related to digestion at all.

• Digestive Symptoms (More Common in Children):
• Bloating
• Constipation
• Diarrhea
• Gas
• Nausea and vomiting
• Abdominal pain
• Stools that are loose, greasy, or foul-smelling¹

Non-Digestive Symptoms (More Common in Adults):

• Anemia (iron deficiency)
• Dermatitis herpetiformis (“gluten rash”)—itchy blisters on the elbows, knees, or scalp
• Fatigue
• Joint or bone pain
• Osteoporosis (loss of bone density)
• Reproductive issues (infertility, miscarriage, delayed puberty)¹ ²

Children with celiac disease may also experience:

• Failure to thrive (poor weight gain)
• Short height or delayed growth
• Neurological issues, including ADHD, headaches, or seizures³

Note: Questhealth.com does not offer testing for individuals under 18 years of age. Please consult with a doctor that could order testing. 

If you experience any of these symptoms, speak with a healthcare provider about celiac disease testing.

Why Should You Get Tested for Celiac Disease?

If you suspect celiac disease, getting tested is important for accurate diagnosis and treatment. Avoiding gluten may improve symptoms, but only proper testing can confirm whether you have celiac disease, gluten intolerance, or a wheat allergy—which are separate conditions requiring different management. Learn more about food allergies.

Additionally, if you stop eating gluten before testing, your results may be inaccurate. Following a gluten-containing diet before celiac disease testing ensures the most reliable results.³ 

If you have a family history of celiac disease your doctor may recommend genetic testing to determine if you have a higher likelihood of developing this disease.⁶

When Should You Get Tested for Celiac Disease?

You should consider getting tested for celiac disease if you:

• Experience persistent digestive issues or unexplained non-digestive symptoms
• Have a family history of celiac disease (as it has a genetic component)
• Have other autoimmune disorders, such as type 1 diabetes or Hashimoto’s thyroiditis
• Plan to start a gluten-free diet—testing before eliminating gluten improves accuracy³

Timing matters: Since celiac disease symptoms can fluctuate, testing while still consuming gluten ensures the best chance of detecting the condition.

What Tests Are Used to Detect Celiac Disease?

The path to determine the presence of celiac disease may be a long one. Celiac disease testing typically begins with a blood antibody test. These tests help to understand if further testing is needed for your immune responses to gluten.

Blood Antibody Test (Celiac (Gluten) Disease Panel available through Quest):

• Measures transglutaminase IgA (tTG-IgA) and immunoglobulin A (IgA) antibodies
• The tTG-IgA test is the preferred initial test for most patients, according to the National Institute for Diabetes and Digestive and Kidney Diseases⁴

Blood tests provide a convenient first step in your journey. When a physician reviews these results one potential outcome may be to recommend further invasive testing such as small intestine biopsy which involves taking tissue sample from the small intestine to check for damage. ¹ 

How Do You Prepare for a Celiac Disease Test?

Preparing for celiac disease testing requires keeping gluten in your diet. If you’ve already gone gluten-free, your test results may be false-negative.

To ensure accurate results:

✔ Continue eating gluten for at least a few weeks before testing.³

✔ No fasting is required for the blood test.

If you're unsure how long to continue consuming gluten, speak with your healthcare provider before getting tested for celiac disease.

How Do You Interpret Celiac Disease Test Results?

It's not easy to simply interpret test results to determine if someone may have celiac disease. Depending on your age, your doctor may request different markers which may include deamidated gliadin peptide (DGP) IgG, transglutaminase (tTg) IgG, tTG IgA, and total Immunoglobulin IgA. Some results will provide a numerical value within a range, indicating if you're below, within, or above reference values. Other results will provide a simple "negative" or "positive" looking for the presence of a specific marker. 

Depending on these results, if they're negative or normal, your physician may look to a different disease being the cause of your distress. If these tests come back abnormal or out of range, your doctor may suggest further testing to confirm a diagnosis.

Some individuals may also require vitamin and mineral deficiency testing, as nutrient absorption is often impacted by celiac disease.⁵ Learn more about the role of vitamins and minerals in your health.

If you test positive, your healthcare provider may also recommend genetic testing for family members to determine their risk.⁶

When you buy a celiac disease test online from Quest, you can consult with an independent physician to review your results and next steps.

Why Buy Your Celiac Disease Test Online from Quest?

Quest makes it easy and convenient to access celiac disease testing without a doctor’s visit. Simply:

1. Purchase your test online
2. Visit a nearby Quest location for sample collection
3. Receive your results quickly and securely

If your results differ from expected ranges, you may receive an alert call from an independent healthcare coordinator. Independent physicians are available to discuss questions or concerns you may have regarding your results.

Buy your celiac disease test

No doctor visit is required to buy your own lab test at questhealth.com. PWNHealth and its affiliates review your purchase to ensure it is medically appropriate before submitting the test order for processing. PWNHealth also reviews your test results and will contact you directly if they require prompt attention. Included in each purchase is the option to discuss your test results with an independent physician; however, you are also encouraged to speak with your primary healthcare provider.