Ask a few adults with celiac disease how they found out, and you’ll hear very different stories. One had stomach trouble for a decade. Another was only being checked for anemia. Another was in her 70s, and everyone assumed the weight loss was just age.

That’s what makes celiac disease in adults so easy to miss. The symptoms change with age, and often they don’t look digestive at all. Below, we walk through what to watch for from your 20s onward, including during pregnancy, and when it makes sense to get tested.

This guide walks through how celiac disease in adults tends to appear at different stages of life, and why the stage you’re in affects what it looks like and how easily it gets missed.

What is celiac disease, and why do adult symptoms vary so much?

Celiac disease is an autoimmune condition. When someone with celiac disease eats gluten, a protein in wheat, barley, and rye, the immune system attacks the lining of the small intestine. Over time, that damage makes it harder to absorb nutrients like iron, calcium, folate, and vitamin D.

That is the same process at every age. What differs is how long it has been going on, what else is happening in your body, and which nutrient shortfalls show up first. Some adults have obvious digestive symptoms. Many don’t, which is why the diagnosis often takes years.

In your 20s and 30s: symptoms that get blamed on stress or a busy life

Younger adults are the group most likely to have the “classic” picture: bloating, diarrhea, gas, cramping, or stomach pain after meals. But even here, it’s easy to explain away. Irritable bowel syndrome, a sensitive stomach, or a stressful job can all take the blame for years.

Other signs in this age group are less obvious:

• Fatigue that doesn’t improve with sleep
• Iron-deficiency anemia, especially without a clear cause
• Mouth ulcers that keep coming back
• An itchy, blistering rash, which can be dermatitis herpetiformis, a skin form of celiac disease
• Headaches, brain fog, or low mood

If digestive symptoms or unexplained anemia have lingered for months, it’s reasonable to ask a doctor about celiac testing, rather than waiting for things to get worse.

In midlife: when it looks like something else

By your 40s and 50s, celiac disease often arrives without any gut symptoms at all. It may be found while looking into:

• Persistent anemia that doesn’t respond to iron the way it should
• Early bone thinning or osteoporosis, particularly in someone who doesn’t have the usual risk factors
• Joint or muscle aches
• Abnormal liver blood tests with no clear explanation
• Tingling or numbness in the hands and feet

Celiac disease is also more common in people with other autoimmune conditions, including type 1 diabetes and autoimmune thyroid disease, so diagnosing them is a good reason to keep celiac in mind.

Midlife is also when symptoms get brushed off as perimenopause, stress, or “just getting older.” If something has been persistently off and no single explanation fits, celiac disease is worth asking about.

After 65: easy to overlook, still worth finding

Some people assume celiac disease is something you’d have noticed long ago. In reality, it can be diagnosed in the seventies, eighties, and beyond. In older adults, the signs overlap with so many other things that celiac disease is rarely the first suspect:

• Unexplained weight loss
• Anemia
• Bone loss or fractures
• Chronic diarrhea or new digestive changes
• Fatigue or weakness blamed on medications or other conditions

Unexplained weight loss, ongoing anemia, or new bowel changes in an older adult always deserve a closer look, and celiac disease is one of several possible causes your doctor may consider. A correct diagnosis at any age allows for treatment and for monitoring bone health and nutrition.

How is celiac disease in adults diagnosed?

Diagnosis usually starts with a blood test for celiac-related antibodies, most commonly tissue transglutaminase IgA (tTG-IgA). If the results point toward celiac disease, a gastroenterologist typically confirms it with an upper endoscopy, during which small tissue samples are taken from the small intestine.

One point matters a great deal: don’t cut gluten out before you’re tested. Going gluten-free first can make test results look normal even when celiac disease is present, and that can delay or cloud the diagnosis. If you’ve already stopped eating gluten, talk to your doctor about how to approach testing safely.

What treatment looks like

The treatment for celiac disease in adults is a strict, lifelong gluten-free diet. There’s no medication that replaces it. Most people notice symptoms improve and the intestine heals over time, though the pace varies from person to person, and some symptoms take longer to settle.

Your doctor may also check for nutritional deficiencies, assess bone health, and arrange follow-up testing to see how you’re responding. Meeting with a dietitian who knows celiac disease can help with the practical side, such as hidden gluten in sauces and packaged foods, and cross-contact in kitchens and restaurants.

Should relatives be tested?

Celiac disease runs in families. Close relatives of someone with a diagnosis are more likely to have it, sometimes without symptoms. If you’ve been diagnosed, ask your doctor whether your parents, brothers, or sisters should be screened.

When to see a doctor

Consider making an appointment if you have any of the following:

• Digestive symptoms like bloating, diarrhea, or abdominal pain that continue for weeks or keep coming back
• Anemia or low iron without a clear cause
• Unexplained weight loss
• Bone loss or osteoporosis that seems out of step with your risk factors
• Fatigue, headaches, or joint pain that never really lifts
• A blistering, itchy rash
• Trouble conceiving or unexplained pregnancy complications
• A close relative with celiac disease, or another autoimmune condition such as type 1 diabetes or thyroid disease

Any of these has other possible causes, so having one doesn’t mean you have celiac

Talk with a gastroenterologist at Digestive Health Services

If you’ve been living with symptoms that haven’t been explained, the gastroenterologists at Digestive Health Services in Downers Grove can help you work out whether celiac disease could be the cause and what to do next.

Book an Appointment Now with Digestive Health Services

This article is for general information only and is not a substitute for professional medical advice, diagnosis, or treatment. Talk to your healthcare provider about your individual situation.