Although celiac disease and gluten intolerance are nearly identical in symptoms, there are some key underlying differences between the two conditions:

Celiac Disease Is an Autoimmune Disorder

Celiac disease is an autoimmune disorder, meaning the immune system mistakenly views the gluten protein as a threat and, in defense efforts against gluten, destroys the lining of the small intestine.

Gluten intolerance is not considered to be an autoimmune issue. However, some emerging research indicates there could be an immune response to gluten intolerance. This response is distinct from celiac disease’s response.

Celiac Disease Damages the Small Intestine

One of the most significant differences between celiac disease and gluten intolerance is that only celiac disease involves damage to the villi, the tiny finger-like tissue lining the small intestine.

When people with celiac disease eat gluten, their immune system destroys the villi, which can lead to difficulty absorbing nutrients. It can also increase the risk of certain cancers, coronary artery disease, autoimmune diseases, and other conditions. People with gluten intolerance do not experience internal damage.

There Is No Definitive Test for Gluten Intolerance

Celiac disease can be diagnosed with an endoscopy (a procedure to view the inside of your small intestine) and a biopsy (removing a small amount of the tissue lining the small intestine). A medical professional will examine this tissue under a microscope to look for damage to the villi.

In contrast, there is currently no definitive test for gluten intolerance. It is a diagnosis of exclusion, meaning it is diagnosed once celiac disease and wheat allergy are ruled out. The person might then be tested for other conditions before following an elimination diet to determine whether gluten or something else is causing their symptoms.

Gluten Tolerance Levels Differ

It’s more important for people with celiac disease to avoid trace amounts of gluten than for people with gluten intolerance. Even tiny amounts of gluten (like a crumb on a cutting board or food cooked in a shared fryer) can damage the small intestine—even if the person experiences no symptoms.

Because people with gluten intolerance do not experience damage to the small intestine, they may still be able to eat some gluten. Some people with gluten intolerance can determine how much gluten they can eat without experiencing symptoms and then stay within that limit.

Only Celiac Disease Is Genetic

Celiac disease is tied to specific genes, which must be activated or “turned on” by something in your environment, like an infection. Not everyone with the genes for celiac disease will develop the condition, but everyone with celiac disease has the genes.

Gluten intolerance is not tied to any specific gene or biomarker. Even if you don’t have celiac genes, you can still have gluten intolerance. The overall cause of gluten intolerance is not well understood.

On the outside, there are many similarities between celiac disease and gluten intolerance. The two conditions share symptoms, triggers, and treatment:

Eating Gluten Triggers Symptoms

In both celiac disease and gluten intolerance, gluten consumption triggers symptoms. This can include anything from eating a slice of bread to consuming trace amounts of gluten on gluten-free bread prepared in a shared toaster.

Both Are Treated With the Gluten-Free Diet

Both celiac disease and gluten intolerance are treated with a gluten-free diet, which involves avoiding any food that contains gluten. This includes foods with wheat, barley, rye, and their derivatives (e.g., beer brewed from barley or soy sauce that contains wheat).

You can’t have both celiac disease and gluten intolerance, as gluten intolerance is the absence of celiac disease with the same symptoms.

Still, the two conditions are closely intertwined. Due to the popularity of the gluten-free diet, gluten intolerance is sometimes incorrectly diagnosed or assumed before celiac disease is tested for. This is a problem because celiac disease tests are only accurate if a person is currently consuming gluten.

Removing gluten from your diet before being tested for celiac disease can result in a false negative. An accurate diagnosis is important because people with celiac disease need to more strictly avoid gluten, including trace amounts, than people with gluten intolerance.

It’s important to get tested for celiac disease before adopting a gluten-free diet or assuming an intolerance.

Talk to your primary healthcare provider if you display symptoms of celiac disease or gluten intolerance. Be sure to mention if you’ve noticed symptoms tied to foods you eat, like meals rich in bread or pasta.

Your healthcare provider may order a blood test for celiac markers. If the test results are positive, they will refer you to a gastroenterologist (a medical doctor who specializes in the digestive tract) for an endoscopy.

If your blood test for celiac disease comes back negative, and you’re currently consuming gluten, then you might have gluten intolerance. However, you may still benefit from seeing a gastroenterologist to have other causes of your symptoms ruled out.

In both cases, talking to a registered dietitian nutritionist can help you adjust to the gluten-free diet and ensure you’re meeting your nutritional needs.

People with celiac disease and gluten intolerance both experience symptoms triggered by eating gluten and need to follow a gluten-free diet.

However, celiac disease is more severe because, unlike gluten intolerance, it’s an autoimmune disease that causes damage to the small intestine.

If you’re concerned about your tolerance to gluten, talk to your healthcare provider about testing for celiac disease before you remove gluten from your diet.