Did you know? An estimated 1 in 100 people in the UK have coeliac disease, but only about 30% are diagnosed. Many suffer for years with "hidden" symptoms that don't seem related to digestion.
When most people think of coeliac disease, they think of stomach pain, bloating, and diarrhea. And yes, those are common symptoms. But coeliac disease is a systemic autoimmune condition that can affect nearly every part of your body. Many people live with undiagnosed coeliac disease for years because their symptoms don't fit the "classic" profile.
Why Symptoms Are So Varied
Coeliac disease damages the small intestine, which is responsible for absorbing nutrients from food. When your body can't properly absorb vitamins, minerals, and other nutrients, it affects everything: your energy, your bones, your skin, your brain, and more.
This is why coeliac disease can show up in so many unexpected ways.
Hidden Symptoms You Shouldn't Ignore
1. Chronic Fatigue (That Never Gets Better)
Not just "I'm tired." We're talking about overwhelming exhaustion that doesn't improve with sleep. You wake up tired. You crash in the afternoon. You can't make it through the day without feeling like you're dragging yourself around.
Why it happens:
Coeliac disease often causes iron-deficiency anemia and vitamin B12 deficiency, both of which lead to severe fatigue. Your body isn't getting the nutrients it needs to produce energy.
2. Unexplained Iron-Deficiency Anemia
Your doctor tells you you're anemic. You take iron supplements, but your levels don't improve. Sound familiar?
Why it happens:
Damaged intestinal villi can't properly absorb iron. Taking supplements won't help if your gut can't absorb them. This is one of the most common hidden signs of coeliac disease.
3. Brain Fog and Difficulty Concentrating
Forgetting words mid-sentence, struggling to focus on simple tasks, feeling mentally "cloudy" or disconnected. Many people with undiagnosed coeliac disease describe this as one of their most frustrating symptoms.
Why it happens:
Inflammation and nutrient deficiencies (especially B vitamins) affect brain function. Some research also suggests gluten antibodies may directly impact the nervous system.
4. Joint Pain and Muscle Aches
Persistent joint pain (often in knees, hips, or wrists), muscle cramps, or general achiness that feels like the flu but never goes away.
Why it happens:
Chronic inflammation from the autoimmune response can cause widespread pain. Calcium and vitamin D malabsorption can also weaken bones and muscles.
5. Skin Rash (Dermatitis Herpetiformis)
An intensely itchy, blistering rash that usually appears on elbows, knees, buttocks, or scalp. It's often misdiagnosed as eczema or psoriasis.
Why it happens:
This is actually a skin manifestation of coeliac disease caused by the same antibodies that attack the intestines. If you have this rash, you almost certainly have coeliac disease.
6. Mood Changes: Depression and Anxiety
Persistent low mood, anxiety, irritability, or even panic attacks that don't seem to have an obvious cause.
Why it happens:
The gut-brain connection is real. Chronic inflammation, nutrient deficiencies, and the stress of feeling unwell can all contribute to mental health symptoms.
Other Hidden Symptoms
• Bone or Tooth Problems
Osteoporosis, frequent fractures, weak or discolored teeth due to poor calcium absorption.
• Reproductive Issues
Irregular periods, infertility, or recurrent miscarriages.
• Mouth Ulcers
Recurrent canker sores that heal slowly or keep coming back.
• Headaches or Migraines
Chronic headaches that don't respond well to typical treatments.
• Tingling or Numbness
Peripheral neuropathy (nerve damage) causing tingling in hands or feet.
• Balance Problems
Unexplained dizziness or coordination issues (ataxia).
When to Get Tested
If you're experiencing several of these symptoms, especially chronic fatigue, anemia, or joint pain that doesn't improve, talk to your doctor about coeliac disease testing.
Important: Do NOT go gluten-free before testing!
You must be eating gluten regularly for accurate test results. If you cut out gluten before being tested, you may get a false negative, delaying your diagnosis even longer.
Trust Your Gut (Literally)
If something feels off and doctors keep dismissing your symptoms, advocate for yourself. Ask specifically about coeliac testing. Many people go years without a diagnosis simply because they didn't know to ask.
Learn More About Coeliac Disease
Read our complete guide to understanding, diagnosing, and managing coeliac disease.
Read Full Guide