Why Autoimmune Disease Is So Common Today

Autoimmune disease has become one of the fastest-growing health concerns of our time. Over 50 million Americans are estimated to have an autoimmune condition, and rates continue to climb each year. Conditions like rheumatoid arthritis, lupus, Hashimoto’s thyroiditis, Crohn’s disease, and psoriasis are no longer rare—they’re increasingly common in everyday practice.

At Sheen Vein (Aesthetics and Functional Medicine) in St. Louis, we see firsthand how autoimmune issues affect patients’ lives—leading to fatigue, pain, digestive problems, rashes, and much more. A common question we hear is: “Why are autoimmune diseases so common now compared to the past?”

The answer is complex, but functional medicine helps us understand the patterns. By addressing root causes such as diet, environment, stress, and gut health, we can often help calm the immune system and restore balance.

What Is Autoimmunity?

The immune system is designed to defend against bacteria, viruses, and toxins. In autoimmune disease, however, the immune system mistakenly attacks the body’s own tissues.

For example:

In Hashimoto’s thyroiditis, the thyroid gland is attacked.
In rheumatoid arthritis, joints are targeted.
In multiple sclerosis, the immune system damages the nervous system.

The result is chronic inflammation, tissue damage, and a wide range of symptoms. But the bigger question is: why is this happening so often now?

1. Environmental Changes and Toxin Exposure

One of the biggest differences between today and a century ago is our exposure to environmental toxins.

Heavy metals such as mercury, lead, and arsenic can disrupt immune balance.
Chemicals in plastics, pesticides, and cleaning products act as endocrine disruptors and immune triggers.
Air pollution contributes to oxidative stress and inflammation.

The immune system is designed to recognize foreign invaders, but constant exposure to chemicals it doesn’t recognize can confuse it, leading to autoimmunity.

At Sheen Vein (Aesthetics and Functional Medicine), we often test for heavy metals, mold toxins, and environmental exposures when evaluating autoimmune patients.

2. Gut Health and the Microbiome

The gut plays a central role in immune regulation. In fact, 70–80% of the immune system resides in the gut. When the gut lining becomes damaged—a condition often referred to as “leaky gut”—immune cells are exposed to food particles and bacteria that should remain inside the digestive tract.

This can trigger immune responses that cross-react with body tissues. Research has linked gut dysbiosis and leaky gut to autoimmune conditions such as celiac disease, type 1 diabetes, and lupus.

Common gut-related triggers include:

Chronic antibiotic use
Diets high in processed foods and low in fiber
Overgrowth of harmful bacteria, yeast, or parasites
Food sensitivities (especially gluten and dairy)

👉 Read our blog on gut dysbiosis and autoimmune disease.

3. Chronic Stress and the Nervous System

Our bodies are designed to handle short-term stress, but chronic stress has become a way of life. Work demands, financial pressure, constant digital stimulation, and lack of downtime keep the nervous system in a constant “fight or flight” state.

This has profound effects on the immune system:

Stress hormones like cortisol suppress and then dysregulate immunity.
Chronic stress increases inflammation.
Sleep disruption weakens immune tolerance.

In functional medicine, we often see stress as the “last straw” that triggers autoimmune flares. Patients may have genetic susceptibility and gut issues, but stress tips the balance toward disease activation.

4. Poor Nutrition and Processed Diets

The standard American diet (SAD) is loaded with processed foods, sugar, refined carbohydrates, and inflammatory oils. At the same time, it is deficient in critical nutrients like magnesium, vitamin D, omega-3 fatty acids, zinc, and selenium—all essential for immune regulation.

Poor nutrition contributes to autoimmune risk in two ways:

Deficiencies – Without enough vitamin D or omega-3s, the immune system cannot regulate itself properly.
Inflammation – High sugar and processed food intake drive chronic inflammation, which triggers immune overactivity.

On the other hand, anti-inflammatory, nutrient-dense diets like the Mediterranean or Paleo approach can reduce autoimmune flares and support healing.

5. Genetics Combined with Modern Triggers

Genetics play a role in autoimmune disease—but genes alone don’t explain the sharp rise in cases. What’s changed is our environmental triggers.

Think of genetics as “loading the gun,” but diet, stress, toxins, and infections “pull the trigger.” This is why one family member may carry a genetic risk but never develop autoimmunity, while another does.

Functional medicine focuses on modifying these environmental triggers to reduce risk and calm existing disease.

6. Hidden Infections

Viral, bacterial, and even fungal infections can act as autoimmune triggers. For example:

Epstein-Barr virus (EBV) has been linked to multiple sclerosis and lupus.
Gut infections like H. pylori or parasites can drive autoimmune thyroid disease.
Chronic Lyme disease may mimic or trigger autoimmune responses.

When the immune system fights infection, it sometimes creates antibodies that cross-react with the body’s own tissues. This “molecular mimicry” is one of the strongest theories explaining autoimmune activation.

Functional Medicine: A Root-Cause Approach

Traditional medicine often manages autoimmune disease with immunosuppressive drugs. While these may reduce symptoms, they do not address the root causes driving immune imbalance.

At Sheen Vein (Aesthetics and Functional Medicine) in St. Louis, we take a comprehensive approach by evaluating:

Gut health with stool and food sensitivity testing
Nutrient levels to identify deficiencies
Hormone balance (thyroid, adrenal, and sex hormones)
Toxin exposure and detoxification ability
Infections or hidden immune triggers

By addressing these areas, we help patients reduce flares, improve energy, and restore quality of life.

Supporting the Immune System Naturally

While every patient plan is individualized, here are some foundational strategies we often recommend:

Eat an anti-inflammatory diet rich in whole foods, vegetables, omega-3s, and fermented foods.
Remove common triggers like gluten, processed sugar, and artificial additives.
Support gut health with probiotics, prebiotics, and digestive support.
Manage stress with mindfulness, yoga, or breathing exercises.
Optimize sleep to restore immune resilience.
Correct deficiencies with targeted supplementation (vitamin D, magnesium, selenium, zinc).

Why Autoimmune Disease Is So Common

The rise in autoimmune disease reflects the way modern life collides with human biology. Our genes haven’t changed, but our environment, diet, stress, and toxin exposures have changed dramatically. The result is an immune system under constant strain, prone to misfiring.

The hopeful news is that by uncovering and addressing these root causes, we can often calm autoimmune activity and help patients regain control of their health.

Take Back Your Health

If you’ve been diagnosed with an autoimmune condition—or suspect you might have one—you don’t have to face it alone. At Sheen Vein (Aesthetics and Functional Medicine) in St. Louis, we specialize in finding the hidden triggers behind autoimmune disease and creating personalized plans to restore balance.

👉 Learn more about our functional medicine approach
👉 Schedule your consultation today

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