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.
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.
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.
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).
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.
Many people experience headaches or migraines once in a while.
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.
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):
- Psoriasis: An inflammatory disease of the skin characterized by scaling and reddening of the skin (27Trusted Source, 28, 29Trusted Source).
- Alopecia areata: An autoimmune disease that appears as non-scarring hair loss (28, 30Trusted Source, 31Trusted Source).
- Chronic urticaria: A skin condition characterized by recurrent, itchy, pink or red lesions with pale centers (32Trusted Source, 33Trusted Source).
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).
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 Source, 41Trusted 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 Source, 45Trusted 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).
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 Source, 55Trusted Source, 56Trusted Source, 57Trusted Source, 58Trusted 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).
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).
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.
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 Source, 71Trusted Source, 72Trusted 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).
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.