Celiac disease causes a wide range of symptoms that go far beyond stomach trouble. While digestive problems like diarrhea, bloating, and abdominal pain are the hallmarks, more than half of adults with the condition experience symptoms that have nothing to do with digestion, including anemia, bone loss, and chronic fatigue. An estimated 80% of people with celiac disease remain undiagnosed, often because their symptoms don’t match what they expect.
Digestive Symptoms
The classic digestive symptoms include bloating, chronic diarrhea, constipation, gas, nausea or vomiting, and abdominal pain. Stools are often loose, greasy, bulky, and foul-smelling, a sign that your body isn’t absorbing fats properly. Some people also develop lactose intolerance because the damage to the small intestine destroys the cells that produce the enzyme needed to break down dairy.
These digestive symptoms are more common in children than in adults. Many adults with celiac disease have mild or intermittent gut issues that are easy to dismiss as irritable bowel syndrome or general food sensitivity. That overlap is one reason the condition takes an average of several years to diagnose in adults.
Symptoms don’t appear immediately after eating gluten. Celiac disease is a delayed immune reaction, with symptoms typically developing 48 to 72 hours after exposure. This lag makes it harder to connect a specific meal to the discomfort that follows, especially if you’re eating gluten regularly and symptoms feel constant.
Symptoms Beyond the Gut
For many adults, the first clues aren’t digestive at all. Iron-deficiency anemia is one of the most common presentations, caused by the damaged intestinal lining failing to absorb iron properly. Persistent fatigue and recurring headaches often accompany it. If you’ve been told your iron levels are low despite eating a normal diet, celiac disease is one of the conditions worth ruling out.
Bone health takes a significant hit as well. Poor absorption of calcium and vitamin D leads to loss of bone density (osteoporosis) or softening of bones (osteomalacia). In children, this same process can cause rickets. Malnutrition from celiac disease can also cause unexplained weight loss, vitamin deficiencies, and general decline in health that seems disproportionate to what you’re eating.
The Celiac Rash
Between 10% and 25% of people with celiac disease develop a specific skin condition called dermatitis herpetiformis. It looks like clusters of intensely itchy bumps on patches of discolored skin, sometimes with small fluid-filled blisters. The rash most commonly appears on the knees, elbows, buttocks, hairline, and scalp.
This rash is so closely linked to celiac disease that its presence is essentially diagnostic. Some people with dermatitis herpetiformis have no noticeable digestive symptoms at all, yet still have the same intestinal damage. The rash clears up on a strict gluten-free diet, though it can take weeks or months to fully resolve.
Neurological Symptoms
Celiac disease can affect the nervous system in ways that aren’t always obvious. Peripheral neuropathy, which causes tingling, numbness, or pain in the hands and feet, has been documented as a complication of the disease. Some people develop problems with balance and coordination linked to damage in the part of the brain that controls movement. Gluten sensitivity is actually a recognized cause of otherwise unexplained cerebellar ataxia, a condition where walking and fine motor control become unsteady.
Migraines and seizures, while less common, also appear in the list of neurological complications, particularly in children with undiagnosed celiac disease.
Symptoms in Children
Children under 3 tend to show the classic digestive picture: abdominal pain, bloating, diarrhea or constipation, nausea, vomiting, and decreased appetite. But the consequences extend further. Poor weight gain, short stature, and failure to grow at a normal rate are red flags, especially when they can’t be explained by other causes. Frequent mouth ulcers and increased fatigue are also common in young children with the disease.
Older children and teenagers can present with what are considered atypical symptoms: delayed puberty, behavioral problems, joint pain, and iron deficiency without obvious dietary explanation. These signs are easy to attribute to other causes, which is why pediatric celiac disease often goes unrecognized for years.
Silent Celiac Disease
Some people with celiac disease have no symptoms at all. This is called silent or asymptomatic celiac disease. These individuals test positive on blood tests and show the characteristic damage to their small intestine on biopsy, yet they feel perfectly fine. The damage is still happening, though, and the long-term risks of untreated celiac disease, including osteoporosis and other complications from malnutrition, still apply.
This is why screening matters even when someone feels healthy. First-degree relatives of someone with celiac disease have a 1 in 10 chance of developing it themselves and should be tested regardless of symptoms. Globally, the prevalence is estimated at about 1.4% based on blood testing, but only about half that number is confirmed by intestinal biopsy, suggesting many cases are caught early or remain borderline.
How Celiac Disease Is Detected
The standard first step is a blood test that measures specific antibodies your immune system produces in response to gluten. This test has a sensitivity between 78% and 100% and a specificity between 90% and 100%, making it a reliable screening tool. A positive result is typically followed by an intestinal biopsy to confirm damage to the lining of the small intestine.
One important detail: you need to be eating gluten regularly for these tests to work. If you’ve already cut gluten from your diet before testing, your antibody levels may have dropped enough to produce a false negative. If you suspect celiac disease, keep gluten in your diet until after testing is complete.