Gluten intolerance is a fairly common concern. It’s characterized by adverse reactions to gluten, a protein found in wheat, barley, and rye.

There are several potential causes of gluten intolerance, including celiac disease, non-celiac gluten sensitivity, and wheat allergy (1Trusted Source).

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

This article will take a closer look at some of the most common symptoms of gluten intolerance.

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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 (2Trusted Source).

It can cause a wide range of symptoms, including skin problems, gastrointestinal issues, mood changes, and more.

Here are a few of the most common symptoms of celiac disease.

1. Diarrhea, constipation, and smelly feces

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 (3Trusted Source).

Frequent diarrhea can cause some major health concerns, such as loss of electrolytes, dehydration, and fatigue (4Trusted Source).

Plus, individuals with celiac disease may experience pale and foul-smelling feces, due to poor nutrient absorption (5Trusted Source).

2. Fatigue

Feeling tired is a common occurrence among people with autoimmune disorders, including celiac disease (6Trusted SourceTrusted Source).

Several factors are thought to contribute to fatigue in individuals with celiac disease, including (6Trusted Source):

  • chronic pain
  • sleep disruptions
  • psychological conditions such as depression

Celiac disease may also be linked to a higher risk of iron-deficiency anemia, a condition that impacts the body’s ability to produce healthy red blood cells (7Trusted Source).

This can cause several serious side effects, including decreased energy levels and fatigue (8Trusted Source).

3. Skin reactions

Gluten intolerance can also affect your skin.

A blistering skin condition called dermatitis herpetiformis is one manifestation of celiac disease (9Trusted Source).

Although everyone who has celiac disease is sensitive to gluten, some people with the condition do not experience digestive symptoms that indicate celiac disease (10).

Furthermore, several other skin conditions have shown improvement while on a gluten-free diet. These include:

4. Depression and anxiety

Depression affects about 6% of adults each year. The symptoms, which often involve feelings of hopelessness and sadness, can have a major effect on daily life (16Trusted Source).

People with digestive issues seem to be more prone to both anxiety and depression than individuals without any underlying conditions (17Trusted Source).

Depression and anxiety are especially common among people who have celiac disease (18Trusted Source19Trusted Source20Trusted Source).

There are a few theories about how gluten intolerance can drive depression. These include:

  • Atypical serotonin levels. Serotonin is a neurotransmitter that allows cells to communicate. It’s commonly known as one of the “happiness” hormones, since decreased levels have been associated with depression (21Trusted 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 (22Trusted 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 (23Trusted Source24Trusted Source).

5. 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 (25Trusted Source).

In one older study in celiac disease patients, two-thirds had lost weight in the 6 months leading up to their diagnosis (26Trusted Source).

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

6. Iron-deficiency anemia

Iron deficiency is the most common nutrient deficiency and accounts for 50% of all anemia cases worldwide (27Trusted Source).

Iron deficiency causes symptoms such as (27Trusted Source):

  • low blood volume
  • fatigue
  • shortness of breath
  • dizziness
  • headaches
  • pale skin
  • weakness

In celiac disease, nutrient absorption in the small intestine is impaired. This results in a reduced amount of iron being absorbed from food (7Trusted Source).

Iron deficiency anemia may be among the first symptoms of celiac disease that a healthcare professional notices (7Trusted Source).

Recent studies suggest that iron deficiency may be significant in both children and adults with celiac disease (28Trusted Source29Trusted Source).

7. Autoimmune disorders

Celiac disease is an autoimmune disease that causes your immune system to attack your digestive tract after you consume gluten (2Trusted Source).

Having this autoimmune condition makes you more prone to other autoimmune condition, such as autoimmune thyroid disease (30Trusted Source31Trusted Source).

And autoimmune thyroid disorders may be a risk factor for developing emotional and depressive disorders (32Trusted Source33Trusted Source34Trusted Source).

This makes celiac disease more common in people who have other autoimmune diseases, such as type 1 diabetes, autoimmune liver diseases, and inflammatory bowel disease (30Trusted Source).

8. Joint and muscle pain

People experience joint and muscle pain for numerous reasons.

There’s a theory that those with celiac disease have a genetically determined oversensitive or overexcitable nervous system.

So, they may have a lower threshold to activate sensory neurons that cause pain in muscles and joints (21Trusted Source35Trusted Source).

9. 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 chronic alcohol misuse (36Trusted Source).

However, some research suggests that individuals with celiac disease could also be at a higher risk of developing this neuropathy, which may be caused by the presence of certain antibodies (37Trusted Source38Trusted SourceTrusted Source).

SUMMARY

Celiac disease is an autoimmune disorder associated with a long list of symptoms, including diarrhea, constipation, fatigue, chronic pain, depression, anxiety, unintentional weight loss, and more.

Although celiac disease is the most severe form of gluten intolerance, 0.5–13% of people may also have non-celiac gluten sensitivity, a milder form of gluten intolerance that can still cause symptoms (39Trusted Source40Trusted Source).

Here are some of the most common symptoms caused by non-celiac gluten sensitivity.

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 uncomfortable (41Trusted 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 concerns among people sensitive or intolerant to gluten (42Trusted Source43Trusted Source).

For instance, one study showed that 87% of people who had suspected non-celiac gluten sensitivity experienced bloating (44Trusted Source).

2. Diarrhea and constipation

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

For people with a sensitivity to gluten, consuming foods that contain gluten can trigger digestive issues (45Trusted SourceTrusted Source46Trusted Source).

In fact, more than 50% of gluten-sensitive individuals regularly experience diarrhea, while about 25% experience constipation (44Trusted Source).

3. Stomach 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 (43Trusted Source).

It’s estimated that up to 83% of those with gluten intolerance experience abdominal pain and discomfort after eating gluten (44Trusted Source).

4. Headaches

Many people experience headaches or migraine attacks once in a while. Migraine is a common condition, affecting roughly 1 in 6 adults in the United States (47Trusted Source).

Still, some studies have shown that gluten-intolerant individuals may be more prone to migraine episodes than others (48Trusted Source49Trusted Source).

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

5. Fatigue

Feeling tired is very common and usually not linked to any condition. However, if you constantly feel very tired, 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 (50Trusted Source51Trusted Source).

According to one study in 486 people with non-celiac gluten sensitivity, 64% reported experiencing tiredness and fatigue (44Trusted Source).

6. Depression and anxiety

Anxiety disorders are believed to affect approximately 33% of people worldwide (52Trusted Source).

Anxiety involves feelings of worry, nervousness, unease and agitation. It often goes hand-in-hand with depression (53Trusted Source).

Individuals with gluten intolerance seem to be more prone to anxiety and depression than individuals without any underlying conditions (54Trusted Source55Trusted Source56Trusted SourceTrusted Source).

For example, in one study, up to 40% of individuals with self-reported gluten sensitivity stated that they regularly experienced anxiety (44Trusted Source).

Several studies have also shown that individuals with depression and self-reported gluten intolerance say they feel better with a gluten-free diet and want to continue it, even if their digestive symptoms aren’t entirely resolved (56Trusted Source57Trusted Source).

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

7. Pain

Gluten exposure may cause inflammation in gluten-sensitive individuals.

The inflammation may result in widespread pain, including in the joints and muscles (44Trusted Source).

People with a gluten sensitivity also seem to be more likely to experience arm and leg numbness (58Trusted Source).

While the exact cause remains unknown, some older studies have linked this symptom to the presence of certain antibodies related to gluten intolerance (59Trusted Source).

8. 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”
  • experiencing mental fatigue

Having a “foggy mind” is a common symptom of gluten intolerance, affecting nearly 40% of gluten-intolerant individuals (44Trusted Source60Trusted Source).

This symptom may be caused by a reaction to certain antibodies in gluten, but the exact reason is unknown (61Trusted Source).

SUMMARY

Non-celiac gluten sensitivity is a form of gluten intolerance that can cause headaches, depression, anxiety, brain fog, fatigue, pain, and digestive problems.

Wheat allergy is a type of food allergy that causes the body’s immune system to react to certain proteins found in wheat, including gluten and other compounds (62Trusted Source).

Wheat allergy is more common among children than adults. In fact, it’s estimated that approximately 65% of children outgrow wheat allergies by age 12 (62Trusted Source).

Here are a few of the most common symptoms of wheat allergy.

1. Skin rash

Like other types of gluten intolerance, wheat allergies may be associated with certain skin conditions.

In particular, wheat allergies can often cause hives. This is a type of skin rash characterized by itching, redness, and inflammation (63Trusted Source).

Typically, this reaction sets in shortly after a person eats wheat products and slowly subsides on its own over time (64Trusted Source).

2. Digestive issues

Studies show that people who are allergic to wheat often report experiencing digestive issues, such as (65Trusted Source):

  • nausea
  • vomiting
  • stomach cramps
  • diarrhea

Food allergies can also trigger other digestive symptoms, including (66Trusted Source):

  • bloating
  • pain
  • indigestion

This is due to the body’s immune response, which is triggered once an allergen, such as wheat, is consumed (67Trusted Source).

3. Nasal congestion

Sneezing, nasal congestion, and a runny nose can also be signs of a wheat allergy (68Trusted Source).

These symptoms are particularly common among individuals with Baker’s asthma. This is an allergic condition caused by frequently breathing in bread flour, resulting in increased sensitivity to wheat or other grains (69Trusted Source).

According to one study in 162 bread factory workers, nearly 89% of those who experienced symptoms of Baker’s asthma also reported nasal symptoms, such as congestion (70Trusted Source).

4. Anaphylaxis

Anaphylaxis is a severe allergic reaction that can be life threatening if left untreated (71Trusted Source).

It can cause a range of serious symptoms, including swelling, hives, nausea, vomiting, and difficulty breathing after exposure to an allergen, such as wheat (71Trusted Source).

Although symptoms usually begin within minutes of exposure, they may also occur up to an hour later (72Trusted Source).

Treatment generally involves the use of epinephrine, a medication that’s injected directly into the skin after the onset of anaphylaxis (73Trusted Source).

SUMMARY

Wheat allergy is a type of food allergy that may cause skin rashes, digestive issues, nasal congestion, and anaphylaxis.

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 to the gluten in your diet. Speak with a healthcare professional about what may be the best options for you.

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