Celiac disease is an autoimmune condition that affects roughly 1 in 100 people worldwide, yet around 80% of those with the disease remain undiagnosed. Unlike common misconceptions, it's not simply a gluten sensitivity or a digestive preference. When someone with celiac disease encounters gluten, their immune system launches an attack on the small intestine's lining, causing inflammation and tissue damage that can affect multiple body systems.

Why Is Celiac Disease So Often Overlooked?

For decades, celiac disease was dismissed as a rare childhood condition characterized by weight loss and chronic diarrhea. This narrow understanding has made the disease remarkably easy to overlook. The average time from symptom onset to diagnosis has historically stretched across years, sometimes more than a decade, because symptoms overlap with so many other conditions.

The core problem is that celiac disease doesn't always look like a gut problem. Many people experience no obvious digestive symptoms at all. Instead, they notice persistent fatigue, anemia that doesn't respond to iron supplements, or unexplained nutrient deficiencies. When someone mentions brain fog or tiredness, it's easy to blame stress or poor sleep rather than consider an autoimmune condition.

One pediatrician living with the diagnosis explained the real-world impact: "I was 24 years old and had a history of microcytic anemia, but had no obvious GI discomfort. I was shocked when my test came back positive," said Dr. Padget Skogman, a board-certified pediatrician. She noted that her own diagnosis came only after her mother was diagnosed with celiac disease in 2008, prompting screening.

Dr. Padget Skogman, a board-certified pediatrician

What Happens Inside the Body When Someone Has Celiac Disease?

In celiac disease, the immune system mistakes gluten, a protein found in wheat, barley, and rye, for a serious threat. The immune system doesn't just target gluten; it damages the body's own tissues, particularly the lining of the small intestine where food is digested and nutrients are absorbed. Over time, this attack destroys tiny, finger-like projections called villi that enable nutrient absorption.

When gluten is present, immune cells become activated and stimulate the production of specific autoantibodies, such as antibodies that target tissue transglutaminase, an enzyme that modifies proteins including gluten. Together, these immune responses fuel chronic inflammation and tissue destruction in the gut and can affect other parts of the body.

How to Recognize Celiac Disease Symptoms Beyond Digestion

Celiac disease can present in many different ways, making it easy to misattribute symptoms to other causes. Here are the key areas where symptoms may appear:

• Blood: Iron-deficiency anemia or deficiencies in B12 or folate that don't improve with supplementation
• Bones: Reduced bone density (osteopenia or osteoporosis) and increased fracture risk, particularly concerning for children and older adults
• Skin: An intensely itchy, blistering rash called dermatitis herpetiformis that can be the only visible sign of the disease
• Nervous system: Headaches, brain fog, peripheral neuropathy (nerve damage), or balance problems
• Reproductive system: Infertility or pregnancy complications in people of childbearing age
• Growth and development: In children, delayed growth or delayed puberty may be the first warning sign
• General symptoms: Fatigue severe enough to disrupt work and daily routines

In some cases, these non-digestive symptoms are the only clues that something is wrong. The result is a condition that can look entirely different from one person to the next, ranging from severe gastrointestinal illness to subtle, system-wide symptoms.

What Genetic and Environmental Factors Trigger Celiac Disease?

Celiac disease develops from a combination of genetic and environmental factors working together. Almost everyone with celiac disease carries a specific genetic variant that affects how their immune system identifies threats. These variants, known as HLA-DQ2 and HLA-DQ8, influence how the immune system reads and responds to proteins like gluten.

However, genetics alone don't cause the disease. Environmental triggers are equally important. Certain infections, particularly gastrointestinal infections early in life, changes in the gut microbiome, or events that disrupt intestinal barrier function may help trigger the disease in genetically susceptible people. Celiac disease can appear at any age, but often emerges during periods of immune or physiological change, such as early childhood, puberty, pregnancy, or after major illness or stress.

Why Diagnosis Matters: The Cost of Delay

Left undiagnosed and untreated, celiac disease can cause lasting damage. The consequences extend far beyond digestive discomfort. Malnutrition, weakened immunity, liver disease, and elevated risk of other autoimmune conditions are all potential outcomes of prolonged undiagnosed celiac disease.

For those already diagnosed, the adjustment can be significant. Dr. Skogman noted that the hardest part initially was finding restaurants that could truly cook celiac-style, gluten-free food without cross-contamination. Even trace amounts of gluten can cause symptoms lasting days. A fryer that cooked something breaded earlier in the day and then fried french fries is enough to trigger a reaction. Cross-contamination isn't a fussy preference; it's the difference between a normal evening and being in pain for the next week.

As awareness grows and more gluten-free products become available, living with celiac disease has become more manageable. However, mental health considerations remain important, particularly for children who must follow a restrictive diet while growing up. Recognizing signs of disordered eating and encouraging open discussion with healthcare providers are essential steps in supporting young people with this diagnosis.