The Hidden Link Between Stress and Disease: What I Learned After Cancer

Jun 8

🎥 Watch the full deep-dive on YouTube — “What I Discovered After Cancer”

They say stress kills—but most people think that’s just a figure of speech. It’s not.

After my cancer diagnosis, I started digging into the science of stress—not just the surface-level stuff like anxiety or burnout, but the full physiological cascade of what happens inside the body. I expected a few interesting takeaways. What I found was more like a horror story with invisible villains.

Stress doesn’t just make you feel overwhelmed. Chronic stress rewires your body’s priorities, dials up inflammation, deregulates your hormones, and—if left unchecked—can literally help cancer spread, drive you toward type 2 diabetes, and damage your heart as badly as smoking. Yet most of us treat it like background noise, something to push through or numb out.

It wasn’t until I saw these changes unfold in my own life that I realized: understanding stress is just as critical as understanding nutrition or exercise. So today, I’m breaking it down—what stress actually is, how it works in your body, and why it might be the most underestimated threat to your long-term health.

Why Stress Isn’t Just a Feeling

Modern life is a minefield of stressors. Work. Bills. Illness. Global crises. Even good things—weddings, promotions, parenting—can stress the system. And yet, we tend to shrug it off. Everyone’s stressed, right?

But stress isn’t just a mood. It’s a full-body event.

At its core, stress is the body’s survival mechanism—an ancient tool designed to save your life. See a lion? Your heart rate spikes. Your liver floods the bloodstream with glucose. Your digestion shuts down. Your muscles tense. It’s go-time.

This is known as the “fight-or-flight” response, and it's useful in short bursts. But when that response gets triggered again and again, day after day, your body starts to suffer.

The Science: Two Key Models of Stress

There are two widely accepted frameworks for understanding stress: the Transactional Model and General Adaptation Syndrome (GAS).

The Transactional Model is psychological. Stress happens when the demands you face exceed the resources you believe you have. If you think you can handle a challenge, you may feel motivated. But if you don’t believe you have what it takes—time, energy, support—you feel trapped. That tension becomes chronic stress.

Then there’s General Adaptation Syndrome, developed by endocrinologist Hans Selye. This model focuses on your body’s physiological response. It has three stages: Alarm, Resistance, and Exhaustion. Initially, your body activates fight-or-flight. If the stressor continues, you enter Resistance—holding the line. But over time, this wears you down, leading to the final stage: Exhaustion. That’s where disease begins to creep in.

When Glucose Becomes a Weapon

During acute stress, your body mobilizes all its energy. Glucose floods your bloodstream so you can run, fight, survive. That’s great—if you’re being chased by a bear.

But if you're stressed every day, your system gets overloaded with sugar. Chronically high blood glucose leads to insulin resistance, a hallmark of type 2 diabetes. Your blood pressure climbs. Your arteries stiffen. Your fat metabolism rewires itself for survival, not longevity.

In short: stress turns your biology against you.

The Silent Threat: Chronic Stress

Here’s the kicker—your body isn’t designed to distinguish between “I might die” and “my boss just emailed me again.” It just responds. And if the stress never stops, the damage accumulates.

That’s what makes chronic stress so dangerous. It’s subtle. It’s normalized. And it’s likely affecting your health right now.

Cancer and Stress: What We Know (and What We Don’t)

There’s no conclusive evidence that chronic stress causes cancer. But if you already have cancer—or if undetected cancer cells are floating in your body—chronic stress makes things worse.

Research shows that stress suppresses p53, a key tumor-suppressor gene. It also promotes angiogenesis—the formation of new blood vessels that tumors need to grow and spread. Worse, stress weakens the immune system’s ability to detect and destroy cancer cells.

I’ve seen this firsthand. I believe my cancer was growing quietly for years. But when I was under extreme stress—during my son’s treatment at St. Jude—I began noticing symptoms. Bleeding. Bowel changes. The stress didn’t cause the cancer, but I believe it accelerated it. And when I returned home and the stress eased, my symptoms backed off.

Diabetes: The Sugar-Stress Spiral

The link between stress and type 2 diabetes is stronger.

Chronic stress raises cortisol, which raises blood glucose. Over time, this leads to insulin resistance—your body’s cells stop responding to insulin, and sugar builds up in the blood. That’s the start of diabetes.

Studies confirm: people under chronic stress are significantly more likely to develop type 2 diabetes. And if you already have it, stress makes it harder to manage, worsening blood sugar levels and long-term complications.

Heart Disease: The Most Dangerous Link of All

Heart disease remains the #1 killer in the world—and stress is a major contributor. Some studies suggest that chronic stress is as harmful as smoking when it comes to cardiovascular risk.

Why? Because chronic stress:

Increases blood pressure
Raises resting heart rate
Promotes inflammation
Triggers glucose and fat imbalances
Accelerates plaque buildup in arteries

All of this leads to a higher risk of heart attack, stroke, and sudden cardiac events. Unlike acute stress, which passes, this is the kind of damage that accumulates slowly—until it doesn’t.

Cancer, Diabetes, Heart Disease: Stress by the Numbers

The data varies by condition, but here’s a rough comparison:

Cancer: Stress doesn’t appear to cause it directly, but can accelerate growth and metastasis if cancer already exists.
Type 2 Diabetes: Stress plays a major role in development and progression, especially via glucose spikes and insulin resistance.
Heart Disease: Chronic stress is nearly as dangerous as smoking, with clear links to hypertension and atherosclerosis.

For all three, stress management isn’t just a luxury—it’s prevention.

Why Managing Stress Could Save Your Life

Exercise. Therapy. Mindfulness. Journaling. Breathing techniques. Social support. All of these can help regulate the stress response. But the biggest shift is recognizing that stress isn’t “just part of life.”

It’s a health risk. One that you can do something about.

You can’t eliminate every stressor. But you can retrain your body’s response to them. And that, more than anything, might be the difference between surviving and thriving—especially if you’re fighting a chronic disease.

Next week, I’ll explore the root causes of stress—from financial pressure to emotional trauma—and how we can better understand which sources we can control.

Then in part three, we’ll talk about evidence-based ways to reduce stress, from ancient practices to modern therapies.

Until then, ask yourself: is stress running my body? Or am I taking the reins?

This article shares personal research and experience; it is not medical advice.

Sources

Have you ever felt your health spiral during a stressful time? Share your experience in the comments—I’d love to hear how you manage it. And stay tuned next week as we unpack the hidden sources of stress you might not even realize are affecting you.

Samuel Chapin