Gluten intolerance typically shows up as symptoms that happen after eating foods with wheat, barley, or rye, and improve when you stop eating them. Common signs include gut issues plus fatigue, headaches, or “brain fog.”

Common symptoms

Watch for symptoms that repeatedly appear within hours to a couple of days after eating gluten-containing foods like bread, pasta, cereals, and baked goods. Typical symptoms include:

• Bloating, gas, stomach pain, or cramps.

• Diarrhea or constipation, sometimes with smelly or greasy stools.

• Nausea or indigestion.

Non‑digestive symptoms

Gluten intolerance and related conditions can also cause body‑wide symptoms.

• Tiredness, low energy, or “brain fog” (trouble focusing, feeling mentally slow).

• Headaches or migraines, joint or muscle pain, and tingling in hands or feet.

• Skin rashes, mood changes, or anemia in more severe or long‑term cases.

When to see a doctor

Because celiac disease, wheat allergy, irritable bowel syndrome, and other issues can look very similar, it is important not to self‑diagnose. See a doctor or gastroenterologist if:

• You have ongoing digestive symptoms, weight loss, or severe fatigue.

• A close family member has celiac disease or gluten intolerance.

Do not stop eating gluten before testing, because blood tests and intestinal biopsies for celiac disease are only accurate if you are still eating gluten regularly.

How gluten issues are diagnosed

For suspected celiac disease, doctors usually order specific blood tests looking for antibodies, and may do an intestinal biopsy to confirm. There is no single definitive test for non‑celiac gluten intolerance; it is usually diagnosed after celiac disease and wheat allergy are ruled out and symptoms improve on a gluten‑free diet.

What you can do now

Until you see a professional, you can:

• Keep a symptom diary noting what you eat (especially gluten foods), when symptoms start, and how severe they are.

• Book an appointment with your primary doctor and ask specifically about testing for celiac disease and other causes of your symptoms.

• Avoid starting a strict gluten‑free diet on your own before testing, but do seek urgent care if you ever have trouble breathing, swelling of lips/tongue, or severe reactions after eating wheat, which can signal an allergy.

If you tell what symptoms you are having and for how long, it is possible to give more tailored suggestions for what to discuss with your doctor.