Nutrition Diet: How do I check if I'm intolerant to gluten?

October 27, 2025 •

4 min read

While celiac disease affects about 1% of the population, non-celiac gluten sensitivity (NCGS) is believed to be more common, affecting a larger percentage of individuals. To determine How do I check if I'm intolerant to gluten?, a systematic process of ruling out other conditions and carefully tracking your body's response is necessary, since no single definitive test exists for NCGS.

Quick Summary

Determining non-celiac gluten sensitivity, or gluten intolerance, requires a medical consultation to first rule out celiac disease and a wheat allergy. The diagnosis is confirmed by monitoring symptom changes during a professionally guided elimination and reintroduction diet.

Key Points

No Single Test: There is no single blood test for non-celiac gluten sensitivity (NCGS); diagnosis is based on excluding other conditions and symptom tracking.
Exclude Celiac Disease First: It is critical to first get tested for celiac disease with a blood test and possibly a biopsy before starting a gluten-free diet, as it affects test accuracy.
Perform an Elimination Diet: The most reliable way to check for gluten intolerance is a controlled elimination and reintroduction diet, where gluten is removed and then carefully added back in.
Track Your Symptoms: Maintain a detailed food and symptom diary throughout the elimination and reintroduction phases to identify potential triggers and patterns.
Understand the Differences: NCGS is not an autoimmune disease like celiac disease, nor is it an allergy like a wheat allergy, but shares overlapping symptoms.
Prevent Cross-Contamination: If you are highly sensitive, take steps to prevent cross-contamination in your kitchen by using separate utensils, toasters, and cutting boards.

Understanding Gluten Sensitivity

Non-celiac gluten sensitivity (NCGS), often referred to as gluten intolerance, is a condition where individuals experience adverse symptoms after consuming gluten, a protein found in wheat, barley, and rye. Unlike celiac disease, which is an autoimmune disorder, and wheat allergy, which involves an allergic reaction, NCGS does not cause intestinal damage. The symptoms, however, can overlap significantly with these other conditions, making proper diagnosis a methodical process of exclusion.

Common Symptoms of Gluten Intolerance

The symptoms of NCGS can vary widely among individuals and often include both gastrointestinal (GI) and non-GI manifestations. They typically appear hours or days after consuming gluten.

Digestive Issues: Abdominal pain, bloating, gas, diarrhea, and constipation are common GI symptoms.
Systemic Symptoms: Non-GI symptoms can include persistent fatigue or tiredness, headaches or brain fog, and joint or muscle pain.
Neurological Effects: Some people report mood changes, anxiety, or numbness in the limbs.
Skin Problems: Skin rashes, eczema, or dermatitis have also been reported.

It is crucial to note that the presence of these symptoms alone does not confirm gluten intolerance, as they can be associated with many other conditions, including irritable bowel syndrome (IBS).

The Diagnostic Process: A Method of Exclusion

Because there is no specific medical test to diagnose non-celiac gluten sensitivity, the diagnosis is one of exclusion. This means a healthcare professional must first rule out celiac disease and wheat allergy, as these conditions require different management strategies. It is vital to perform these tests before you start a gluten-free diet, as removing gluten can affect the accuracy of the results.

Step 1: Rule Out Celiac Disease

Your doctor will likely order blood tests to check for specific antibodies that indicate an immune reaction to gluten, such as the tissue transglutaminase (tTG-IgA) test. If blood test results are positive, a small intestine biopsy may be performed to check for damage to the gut lining, which is characteristic of celiac disease. Genetic testing for HLA-DQ2 and HLA-DQ8 genes can also be used to help rule out celiac disease if they are absent, though having these genes does not guarantee a diagnosis.

Step 2: Rule Out Wheat Allergy

For a wheat allergy, an allergist can perform tests like a skin-prick test or blood test (IgE assay) to see if you have an immune system reaction to wheat proteins. Symptoms of a wheat allergy typically appear more quickly and can include hives, difficulty breathing, or swelling.

Step 3: The Elimination and Reintroduction Diet

Once celiac disease and wheat allergy have been ruled out, the gold standard for diagnosing NCGS is an elimination and reintroduction diet, ideally conducted under a doctor's or dietitian's supervision.

Elimination Phase: Remove all sources of gluten from your diet for a minimum of six weeks. Keep a detailed food and symptom diary, noting any changes. Many people report significant improvement in symptoms during this phase.
Reintroduction Phase: Gradually reintroduce gluten back into your diet. This must be done carefully to monitor for symptom recurrence. The Cleveland Clinic recommends reintroducing gluten gradually over a period of time. If your symptoms return after reintroducing gluten, it provides strong evidence for NCGS.

Comparison of Gluten-Related Conditions


Feature	Celiac Disease	Non-Celiac Gluten Sensitivity (NCGS)	Wheat Allergy
Immune Response	Autoimmune disease where the body attacks its own small intestine.	Innate immune response; not considered autoimmune or allergic.	Allergic reaction involving IgE antibodies.
Intestinal Damage	Causes chronic inflammation and damage to the lining of the small intestine.	No intestinal damage occurs.	No intestinal damage; symptoms are from an allergic reaction.
Symptoms	Wide range of symptoms, including diarrhea, fatigue, bloating, and nutrient deficiencies.	Similar to celiac, but often more extra-intestinal symptoms like brain fog, headache, and joint pain.	Rapid onset of symptoms like hives, itching, or respiratory issues after eating wheat.
Diagnosis	Blood tests for specific antibodies (tTG-IgA) followed by a small intestine biopsy.	Diagnosis of exclusion; requires ruling out celiac and allergy, confirmed by elimination diet.	Skin-prick or blood tests (IgE assay) by an allergist.
Treatment	Strict, lifelong gluten-free diet is mandatory.	Gluten-free diet or managed reduction of gluten intake to control symptoms.	Avoidance of wheat; not necessarily all gluten-containing grains.

Managing Your Diet: What to Eat and Avoid

If you've determined you are intolerant to gluten, managing your diet is key to symptom relief. A well-planned gluten-free diet can be nutritious and satisfying. A registered dietitian can provide invaluable support in ensuring you are receiving all the necessary nutrients.

Foods Containing Gluten (to Avoid):

Grains: Wheat, barley, rye, and triticale.
Baked Goods: Bread, cakes, cookies, and pastries made with wheat flour.
Pasta: All wheat-based pastas.
Cereals: Many breakfast cereals, unless explicitly labeled gluten-free.
Sauces & Condiments: Soy sauce, marinades, some salad dressings, and gravies often contain gluten.
Snacks: Pretzels, crackers, and many processed snack foods.
Beverages: Beer, ales, and stouts.

Naturally Gluten-Free Foods (to Enjoy):

Fruits and Vegetables: Fresh, unprocessed fruits and vegetables are naturally gluten-free.
Protein: Meat, fish, poultry, eggs, beans, and nuts are all great protein sources.
Dairy: Plain milk, cheese, and yogurt are safe choices.
Grains: Many grains are naturally gluten-free, including rice, quinoa, millet, and corn.

Preventing Cross-Contamination

For those with high sensitivity, cross-contamination is a serious concern. To prevent this, consider using separate cooking utensils, cutting boards, toasters, and condiments for gluten-free foods.

Conclusion

While the path to discovering a gluten intolerance can be complex, it is a manageable health concern once properly identified. The most reliable method involves a medical professional ruling out celiac disease and wheat allergy, followed by a closely monitored gluten elimination and reintroduction diet. By listening to your body, collaborating with healthcare providers, and committing to a supportive nutrition diet, you can find relief from your symptoms and significantly improve your quality of life.

For more detailed information on living a gluten-free lifestyle, consult with a qualified dietitian or visit an authoritative source like the Celiac Disease Foundation.

Frequently Asked Questions

Gluten intolerance, or NCGS, causes unpleasant symptoms but no intestinal damage, whereas celiac disease is an autoimmune disorder that triggers immune system attacks, causing permanent damage to the small intestine.

There is no definitive biomarker or antibody test for NCGS. Its diagnosis relies on ruling out other conditions like celiac disease and wheat allergy, and then observing the improvement of symptoms on a gluten-free diet.

No. While some at-home tests can provide genetic information related to celiac disease, they cannot replace clinical testing or a professional diagnosis. Starting a gluten-free diet based on these without medical guidance can complicate a correct diagnosis.

The elimination diet involves completely removing gluten from your diet for several weeks to see if symptoms improve. If they do, gluten is reintroduced to see if the symptoms return, confirming the intolerance.

Yes, it is highly recommended to consult a doctor first. They can perform necessary tests to rule out more serious conditions like celiac disease or a wheat allergy before you begin the elimination diet.

If your symptoms persist, it is important to return to your doctor or gastroenterologist. Other issues, such as small intestinal bacterial overgrowth (SIBO) or irritable bowel syndrome, may be the cause.

Beyond digestive upset, common non-digestive symptoms include persistent fatigue, headaches, brain fog, joint or muscle pain, and skin rashes.

You can eat plenty of naturally gluten-free foods, including fresh fruits and vegetables, meat, fish, eggs, dairy, rice, and quinoa. Many gluten-free alternative products are also available.