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What Are 9 Signs You May Be Gluten Intolerant?

Medically reviewed by Carmen Pope, BPharm. Last updated on May 10, 2023.

Official answer


1. Bloating For No Reason Or After Certain Foods

No doubt all of us have experienced bloating at some stage, usually associated with overindulgence after special occasions, such as Thanksgiving.

But bloating for no particular reason, or only associated with certain foods, such as bread, pastries, or some sauces, may be a sign of gluten intolerance. Gluten intolerance is a term used to describe sensitivity to gluten - and this includes people with Celiac disease (an inherited autoimmune disorder that damages the small intestine), wheat allergy, and non-celiac gluten sensitivity. If there is no particular reason for your bloating or you are experiencing it regularly - get it checked out!

2. Changes In Your Bowels

There are over 300 known symptoms of gluten intolerance so obviously symptoms vary from person to person.

Then it probably comes as no surprise to learn that some people develop constipation (the passing of infrequent, hard stools) while others experience loose, foul-smelling diarrhea (the passing of frequent, soft, or liquid stools).

However, several other conditions can also cause changes in your bowel habits. For this reason, your doctor may need to run a few tests to rule out other causes.

3. Tiredness Or Fatigue

People with celiac disease often feel tired all the time. This is because their intestines can't absorb valuable nutrients and vitamins needed to provide energy.

Tiredness can also be a symptom of other conditions such as anemia, chronic fatigue syndrome, sleep disorders, thyroid problems, and diabetes.

4. An Incredibly Itchy Rash On Certain Parts of the Body

Approximately one in four people with celiac disease develop an intensely itchy rash usually on their elbows, knees, buttocks, back, and back of the neck.

The medical term for this rash is Dermatitis Herpetiformis (DH) and it is characterized by clusters of small blisters. Interestingly, people with this rash typically have no digestive symptoms of celiac disease.

5. Delayed Growth Or Weight Loss

Undiagnosed celiac disease in children can starve them of valuable nutrients needed for growth and development. The growth rate may also be slowed.

Both adults and children already diagnosed with celiac disease can experience weight loss, despite having a normal appetite. This is because even small amounts of gluten cause damage to the lining of the intestines, resulting in malabsorption. This damage can persist for years in adults, even after switching to a gluten-free diet.

6. Mouth Ulcers or Canker Sores

Canker sores (aphthous ulcers) are painful, small crater-like sores that develop on the inner cheeks, gum, tongue, or roof of the mouth. The cause of canker sores has eluded scientists for years, but stress, infection, trauma, and certain foods are known triggers.

However, for a small minority of people, gluten intolerance may be the culprit. In one research study, over 240 patients with recurrent mouth ulcers were screened for celiac disease, and seven were confirmed to have the disorder. Interestingly, all seven had failed to respond to routine anti-mouth ulcer medications, and in all, canker sores were their only noticeable symptom.

7. Restless Legs Syndrome

Restless legs syndrome (RLS) is a nerve disorder characterized by throbbing, pulling, creeping, or other unpleasant sensations in the legs and an uncontrollable, usually overwhelming, urge to move them.

Studies have determined that up to 35% of people with celiac disease suffer from RLS. People with both disorders may also be iron deficient. For many people with celiac disease and RLS, following a gluten-free diet relieves RLS symptoms.

8. Depression, Irritability, And Behavioral Problems

Gluten can have profound psychological effects on people with celiac disease.

Mood swings, anxiety, and depression are common among adults with undiagnosed gluten sensitivity. In children, tantrums, irritability, and even ADHD can manifest. Some researchers estimate neurological disorders may occur in as many as 10-25% of all celiac patients.

Ask your doctor to test for celiac disease, non-celiac gluten sensitivity, and wheat allergies, particularly if you have a child that has been diagnosed with a behavioral, mental health, or developmental disorder.

9. Anemia

Iron-deficiency anemia is reasonably common in people with undiagnosed Celiac disease because they're not absorbing enough iron from the food they eat.
The overreaction of your body's immune system to gluten damages the tiny, hairlike projections (villi) that line your small intestine preventing vital nutrients, such as iron, from being absorbed.

However, your intestinal lining will begin to heal once you are diagnosed with Celiac disease and start a gluten-free diet, and nutrients will be absorbed again, although your doctor may tell you to take iron supplements or increase your intake of iron-rich foods initially.

  • Celiac disease. Mayo clinic 2023.
  • Igbinedion SO, Ansari J, Vasikaran A, et al. Non-celiac gluten sensitivity: All wheat attack is not celiac. World J Gastroenterol. 2017;23(40):7201-7210. doi:10.3748/wjg.v23.i40.7201
  • Leonard MM, Vasagar B. US perspective on gluten-related diseases. Clin Exp Gastroenterol. 2014;7:25-37. Published 2014 Jan 24. doi:10.2147/CEG.S54567
  • Symptoms of non-celiac gluten sensitivity. Beyond Celiac. 2023.

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