The 14 Most Common Signs of Gluten Intolerance

Gluten intolerance is a fairly common problem.

It is characterized by adverse reactions to gluten, a protein found in wheat, barley and rye.

Celiac disease is the most severe form of gluten intolerance.

It is an autoimmune disease that affects about 1% of the population and may lead to damage in the digestive system (1Trusted Source2Trusted Source).

However, 0.5–13% of people may also have non-celiac gluten sensitivity, a milder form of gluten intolerance that can still cause problems (3Trusted Source4Trusted Source).

Both forms of gluten intolerance can cause widespread symptoms, many of which have nothing to do with digestion.

Here are the 14 main signs and symptoms of gluten intolerance.

  • 1. Bloating

    Bloating is when you feel as if your belly is swollen or full of gas after you’ve eaten. This can make you feel miserable (5Trusted Source).

    Although bloating is very common and can have many explanations, it may also be a sign of gluten intolerance.

    In fact, feeling bloated is one of the most common complaints of people who are sensitive or intolerant to gluten (6Trusted Source7Trusted Source).

    One study showed that 87% of people who had suspected non-celiac gluten sensitivity experienced bloating (8Trusted Source).

  • 2. Diarrhea, Constipation and Smelly Feces

    Occasionally getting diarrhea and constipation is normal, but it may be a cause for concern if it happens regularly.

    These also happen to be a common symptom of gluten intolerance.

    Individuals with celiac disease experience inflammation in the small intestine after eating gluten.

    This damages the gut lining and leads to poor nutrient absorption, resulting in significant digestive discomfort and frequent diarrhea or constipation (9Trusted Source).

    However, gluten may also cause digestive symptoms in some people who don’t have celiac disease (10Trusted Source11Trusted Source12Trusted Source13Trusted Source).

    More than 50% of gluten-sensitive individuals regularly experience diarrhea, while about 25% experience constipation (8Trusted Source).

    Furthermore, individuals with celiac disease may experience pale and foul-smelling feces due to poor nutrient absorption.

    Frequent diarrhea can cause some major health concerns, such as loss of electrolytes, dehydration and fatigue (14Trusted Source).

  • 3. Abdominal Pain

    Abdominal pain is very common and can have numerous explanations.

    However, it is also the single most common symptom of an intolerance to gluten (13Trusted Source15Trusted Source16Trusted Source).

    Up to 83% of those with gluten intolerance experience abdominal pain and discomfort after eating gluten (8Trusted Source17Trusted Source).

  • 4. Headaches

    Many people experience headaches or migraines once in a while.

    Migraines are a common condition, with 10–12% of the Western population experiencing them regularly (18Trusted Source19Trusted Source).

    Interestingly, studies have shown that gluten-intolerant individuals may be more prone to migraines than others (20Trusted Source21Trusted Source).

    If you have regular headaches or migraines without any apparent cause, you could be sensitive to gluten.

  • 5. Feeling Tired

    Feeling tired is very common and usually not linked to any disease.

    However, if you constantly feel very tired, then you should explore the possibility of an underlying cause.

    Gluten-intolerant individuals are very prone to fatigue and tiredness, especially after eating foods that contain gluten (22Trusted Source23Trusted Source).

    Studies have shown that 60–82% of gluten-intolerant individuals commonly experience tiredness and fatigue (8Trusted Source23Trusted Source).

    Furthermore, gluten intolerance can also cause iron-deficiency anemia, which in turn will cause more tiredness and lack of energy (24Trusted Source).

  • 6. Skin Problems

    Gluten intolerance can also affect your skin.

    A blistering skin condition called dermatitis herpetiformis is the skin manifestation of celiac disease (25Trusted Source).

    Everyone who has the disease is sensitive to gluten, but less than 10% of patients experience digestive symptoms that indicate celiac disease (25Trusted Source).

    Furthermore, several other skin diseases have shown improvement while on a gluten-free diet. These include (26Trusted Source):

  • 7. Depression

    Depression affects about 6% of adults each year. The symptoms can be very disabling and involve feelings of hopelessness and sadness (34Trusted Source).

    People with digestive issues seem to be more prone to both anxiety and depression, compared to healthy individuals (35Trusted Source).

    This is especially common among people who have celiac disease (36Trusted Source37Trusted Source38Trusted Source39Trusted Source).

    There are a few theories about how gluten intolerance can drive depression. These include (40Trusted Source):

    • Abnormal serotonin levels: Serotonin is a neurotransmitter that allows cells to communicate. It is commonly known as one of the “happiness” hormones. Decreased amounts of it have been linked with depression (37Trusted Source41Trusted Source).
    • Gluten exorphins: These peptides are formed during the digestion of some of the gluten proteins. They may interfere with the central nervous system, which may raise the risk of depression (42Trusted Source).
    • Changes in the gut microbiota: Increased amounts of harmful bacteria and decreased amounts of beneficial bacteria may affect the central nervous system, increasing the risk of depression (43Trusted Source).

    Several studies have shown that depressed individuals with self-reported gluten intolerance want to continue a gluten-free diet because they feel better, even though their digestive symptoms may not be resolved (44Trusted Source45Trusted Source).


    That suggests that gluten exposure on its own may induce feelings of depression, irrespective to digestive symptoms.

  • 8. Unexplained Weight Loss

    An unexpected weight change is often a cause for concern.

    Although it can stem from various reasons, unexplained weight loss is a common side effect of undiagnosed celiac disease (46Trusted Source).

    In one study in celiac disease patients, two-thirds had lost weight in the six months leading up to their diagnosis (17Trusted Source).

    The weight loss may be explained by a variety of digestive symptoms, coupled with poor nutrient absorption.

  • 9. Iron-Deficiency Anemia

    Iron-deficiency anemia is the most common nutrient deficiency in the world and accounts for anemia in 5% and 2% of American women and men, respectively (47Trusted Source).

    Iron deficiency causes symptoms such as low blood volume, fatigue, shortness of breath, dizziness, headaches, pale skin and weakness (48Trusted Source).

    In celiac disease, nutrient absorption in the small intestine is impaired, resulting in a reduced amount of iron being absorbed from food (49Trusted Source).

    Iron deficiency anemia may be among the first symptoms of celiac disease that your doctor notices (50Trusted Source).

    Recent studies suggest that iron deficiency may be significant in both children and adults with celiac disease (51Trusted Source52Trusted Source).

  • 10. Anxiety

    Anxiety may affect 3–30% of people worldwide (53Trusted Source).

    It involves feelings of worry, nervousness, unease and agitation. Furthermore, it often goes hand-in-hand with depression (54Trusted Source).

    Individuals with gluten intolerance seem to be more prone to anxiety and panic disorders than healthy individuals (39Trusted Source55Trusted Source56Trusted Source57Trusted Source58Trusted Source).

    Additionally, a study showed that up to 40% of individuals with self-reported gluten sensitivity stated that they regularly experienced anxiety (8Trusted Source).

  • 11. Autoimmune Disorders

    Celiac disease is an autoimmune disease that causes your immune system to attack your digestive tract after you consume gluten (59Trusted Source).

    Interestingly, having this autoimmune disease makes you more prone to other autoimmune diseases, such as autoimmune thyroid disease (60Trusted Source61Trusted Source).

    Furthermore, autoimmune thyroid disorders may be a risk factor for developing emotional and depressive disorders (62Trusted Source63Trusted Source64Trusted Source).

    This also makes celiac disease more common in people that have other autoimmune diseases, such as type 1 diabetes, autoimmune liver diseases and inflammatory bowel disease (61Trusted Source).

    However, non-celiac gluten sensitivity has not been associated with an increased risk of autoimmune disorders, malabsorption or nutritional deficiencies (65Trusted Source66Trusted Source).

  • 12. Joint and Muscle Pain

    There are numerous reasons why people experience joint and muscle pain.

    There is a theory that those with celiac disease have a genetically determined over-sensitive or over-excitable nervous system.

    Therefore, they may have a lower threshold to activate sensory neurons that cause pain in muscles and joints (67Trusted Source68Trusted Source).

    Moreover, gluten exposure may cause inflammation in gluten-sensitive individuals. The inflammation may result in widespread pain, including in joints and muscles (8Trusted Source).

  • 13. Leg or Arm Numbness

    Another surprising symptom of gluten intolerance is neuropathy, which involves numbness or tingling in the arms and legs.

    This condition is common in individuals with diabetes and vitamin B12 deficiency. It can also be caused by toxicity and alcohol consumption (69Trusted Source).

    However, individuals with celiac disease and gluten sensitivity seem to be at a higher risk of experiencing arm and leg numbness, compared to healthy control groups (70Trusted Source71Trusted Source72Trusted Source).

    While the exact cause is not known, some have linked this symptom to the presence of certain antibodies related to gluten intolerance (73Trusted Source).

  • 14. Brain Fog

    “Brain fog” refers to the feeling of being unable to think clearly.

    People have described it as being forgetful, having difficulty thinking, feeling cloudy and having mental fatigue (74Trusted Source).

    Having a “foggy mind” is a common symptom of gluten intolerance, affecting up to 40% of gluten-intolerant individuals (8Trusted Source75Trusted Source76Trusted Source).

    This symptom may be caused by a reaction to certain antibodies in gluten, but the exact reason is unknown (77Trusted Source78Trusted Source).

Take Home Message

Gluten intolerance can have numerous symptoms.

However, keep in mind that most of the symptoms on the list above may have other explanations as well.

Nevertheless, if you regularly experience some of them without an apparent cause, then you may be reacting negatively to the gluten in your diet.

In this case, you should consult with a doctor or try temporarily removing gluten from your diet to see if it helps. If you don’t already have a physician, you can use the Healthline FindCare tool to find a provider near you.

Original source