How to tell if you have gluten intolerance? Navigating the signs and diagnosis

October 13, 2025 •

5 min read

An estimated 6% of the U.S. population is believed to have non-celiac gluten sensitivity (NCGS), commonly known as gluten intolerance. If you frequently experience digestive issues or other symptoms after eating foods with wheat, rye, or barley, you may wonder how to tell if you have gluten intolerance.

Quick Summary

This article outlines the common symptoms, diagnostic steps, and management of gluten intolerance, or non-celiac gluten sensitivity. It differentiates it from celiac disease and wheat allergy, explaining the medical process that involves ruling out other conditions and observing dietary responses.

Key Points

Symptom Overlap: Gluten intolerance symptoms can be similar to celiac disease and IBS, requiring professional diagnosis to differentiate.
Diagnosis by Exclusion: Non-celiac gluten sensitivity is confirmed by ruling out celiac disease and wheat allergy before an elimination diet.
Importance of a Gluten Challenge: A medically supervised reintroduction of gluten after an elimination diet is the key diagnostic tool for NCGS.
Dietary Management is Key: The primary treatment for gluten intolerance is a gluten-free or low-gluten diet tailored to individual tolerance levels.
Professional Guidance is Recommended: Consulting a gastroenterologist and a registered dietitian ensures an accurate diagnosis and a nutritionally balanced diet plan.
Read Labels and Prevent Cross-Contamination: Careful attention to food labels and kitchen habits is crucial for effectively managing a gluten-free diet.

Understanding the Landscape of Gluten-Related Disorders

Before determining how to tell if you have gluten intolerance, it's essential to understand that not all adverse reactions to gluten are the same. There are three primary conditions to consider: celiac disease, wheat allergy, and non-celiac gluten sensitivity (NCGS), which is what is commonly referred to as gluten intolerance.

Celiac Disease

Celiac disease is a serious, lifelong autoimmune disorder. For individuals with this condition, consuming gluten triggers an immune response that damages the lining of the small intestine. This damage can lead to malnutrition and other serious health problems if left untreated. Diagnosis is typically confirmed through blood tests and a small intestine biopsy. A strict, lifelong gluten-free diet is the only effective treatment.

Wheat Allergy

Different from both celiac disease and NCGS, a wheat allergy is an immune-system-mediated response to proteins found in wheat. Allergic reactions are typically immediate and can range from hives and sneezing to, in severe cases, anaphylaxis. A wheat allergy is diagnosed with a skin-prick test or blood test and does not cause the intestinal damage associated with celiac disease.

Non-Celiac Gluten Sensitivity (NCGS)

Also known as gluten intolerance, NCGS is a condition where individuals experience symptoms after eating gluten but test negative for both celiac disease and wheat allergy. The exact mechanism is not fully understood, but it does not cause the intestinal damage characteristic of celiac disease. Diagnosis is based on a process of exclusion, followed by an elimination diet.

Key Signs and Symptoms to Monitor

Symptoms of gluten intolerance can be wide-ranging and often mimic other conditions like irritable bowel syndrome (IBS). It's important to pay attention to both digestive and non-digestive signs.

Digestive Symptoms

Bloating and Gas: A common and often immediate response to consuming gluten.
Abdominal Pain: Discomfort or pain in the stomach area after eating gluten-containing foods.
Diarrhea or Constipation: Irregular bowel movements are a hallmark of NCGS.
Nausea: A feeling of sickness after meals with gluten.

Non-Digestive Symptoms

Fatigue or "Brain Fog": Experiencing unexplained tiredness or difficulty concentrating, especially after eating.
Headaches: Frequent headaches or migraines are reported by many with gluten sensitivity.
Joint and Muscle Pain: Chronic pain and inflammation in joints and muscles can be a symptom.
Skin Rashes: Conditions like eczema or a specific itchy, blistering rash called dermatitis herpetiformis can sometimes occur.
Mood Changes: Anxiety, depression, or heightened irritability have been associated with NCGS.
Neurological Symptoms: Numbness or tingling in the limbs (peripheral neuropathy) is also a potential sign.

The Professional Diagnostic Process

If you suspect you have a gluten intolerance, it is crucial to consult a healthcare professional, such as a gastroenterologist, rather than self-diagnosing. The process for confirming NCGS is one of elimination.

The Steps to a Diagnosis

Do Not Eliminate Gluten Yet: For accurate testing, you must be on a regular gluten-containing diet. Going gluten-free prematurely can lead to false negative test results for celiac disease.
Screen for Celiac Disease: Your doctor will order blood tests to check for specific antibodies associated with celiac disease. If these are positive, or if symptoms are severe, an endoscopy may be performed to examine and biopsy the small intestine.
Test for Wheat Allergy: Your doctor may also perform tests, such as a skin prick test, to rule out a wheat allergy.
Perform an Elimination Diet: If both celiac disease and wheat allergy are ruled out, your doctor will likely recommend a medically supervised gluten-free elimination diet for several weeks.
Reintroduce Gluten (The Gluten Challenge): After the elimination period, you will reintroduce gluten to see if symptoms return. The recurrence of symptoms after reintroduction is key to diagnosing NCGS.

Distinguishing Between Conditions: A Comparison

To help clarify the differences, this table highlights the key characteristics of celiac disease, non-celiac gluten sensitivity, and wheat allergy.


Feature	Celiac Disease	Non-Celiac Gluten Sensitivity	Wheat Allergy
Cause	Autoimmune disorder; gluten triggers immune attack on small intestine.	Adverse reaction to gluten (or other wheat components); not autoimmune or allergic.	Immune system overreaction to wheat proteins.
Damage	Causes permanent damage to the small intestine's villi.	Does not cause intestinal damage.	No intestinal damage; can cause dangerous allergic reactions.
Diagnosis	Blood tests (antibodies) and small intestine biopsy.	Diagnosis of exclusion; confirmed via elimination diet and gluten challenge.	Skin prick or blood tests (IgE antibodies).
Severity	Serious, lifelong condition with potential for long-term health complications.	Uncomfortable symptoms that can be managed by diet.	Varies from mild to severe, potentially life-threatening.
Dietary Action	Strict, lifelong gluten-free diet is mandatory.	Strictness can vary; some may tolerate small amounts.	Strict avoidance of wheat, not necessarily all gluten.

Navigating a Gluten-Free Lifestyle

Once a diagnosis of NCGS is confirmed, managing the condition involves careful dietary choices. A gluten-free diet is the most effective way to manage symptoms, but unlike celiac disease, the strictness can sometimes be tailored to individual tolerance levels.

Essential Tips for a Gluten-Free Diet

Focus on Naturally Gluten-Free Foods: Base your meals on fruits, vegetables, meat, fish, poultry, eggs, and dairy products.
Embrace Gluten-Free Grains: Explore alternatives like quinoa, rice, corn, millet, and buckwheat.
Become a Label Reader: Gluten can be hidden in many processed foods under various names like malt, hydrolyzed vegetable protein, and certain starches. Always check the ingredients list. The FDA has specific labeling rules for products marked "gluten-free".
Beware of Cross-Contamination: In a household with mixed diets, it's crucial to prevent gluten-free foods from coming into contact with gluten-containing ones. This includes using separate toasters, cutting boards, and condiment containers.
Consult a Dietitian: Working with a registered dietitian is highly recommended to ensure your gluten-free diet is nutritionally balanced and to help navigate the initial changes.

Potential Nutritional Risks of Going Gluten-Free

Fiber Deficiency: Many high-fiber foods contain gluten. Ensure you replace lost fiber with other sources like legumes, nuts, seeds, and gluten-free whole grains.
Nutrient Deficiencies: Gluten-free packaged products may lack certain vitamins and minerals, including B vitamins, folate, and iron. Pay attention to getting these from a varied diet or discuss supplements with your doctor.

Conclusion

Learning how to tell if you have gluten intolerance is a process that requires patience, observation, and medical collaboration. Distinguishing between NCGS, celiac disease, and a wheat allergy is a critical first step, as their management strategies differ significantly. While there is no single test for gluten intolerance, a professional-guided elimination diet and gluten challenge can provide a clear diagnosis. With accurate information and careful dietary management, it is entirely possible to live a healthy, symptom-free life. Seeking expert guidance from both a physician and a registered dietitian will ensure you are making informed decisions about your nutrition and overall well-being.

Visit the Celiac Disease Foundation for more information on gluten-related disorders.

Frequently Asked Questions

Common symptoms include bloating, gas, abdominal pain, diarrhea, constipation, fatigue, brain fog, headaches, and joint pain.

Diagnosis is a process of exclusion. A doctor will first rule out celiac disease and wheat allergy. If those tests are negative, a supervised gluten-free elimination diet followed by a gluten challenge is used to confirm the diagnosis.

No, there is currently no specific, validated blood test for non-celiac gluten sensitivity. It is diagnosed based on symptom improvement on a gluten-free diet and symptom return upon reintroduction of gluten.

Symptoms typically begin to improve within days or a couple of weeks of starting a gluten-free diet, although it may take longer for extra-intestinal symptoms to resolve.

Yes, it is possible to develop non-celiac gluten sensitivity at any age. While some people are born with it, others develop it later in life.

For many, gluten intolerance is a long-term condition managed through diet, though some may find their sensitivity decreases over time with dietary and lifestyle adjustments. The condition's permanence is not fully understood, and monitoring with a healthcare provider is recommended.

For celiac disease, a strict, lifelong gluten-free diet with no cross-contamination is essential. For NCGS, a strict diet is often not required, and some individuals may tolerate small amounts of gluten.

Yes, there is significant overlap between irritable bowel syndrome (IBS) and non-celiac gluten sensitivity regarding gastrointestinal symptoms. A gluten challenge is often used to help differentiate the two.