It may be the disease of our time. Stress and stress related illnesses are on the rise—with 44% of Americans reporting an increase in psychological stress in just the past five years. The American Psychological Association warns that we are a nation on the verge of a stress-induced public health crisis.
Stress in everyday life is only partly to blame. The crisis is compounded by how we respond: overwhelmed by stress, we often view lifestyle and behavioral changes needed to mitigate stress as insurmountable. We get trapped in a vicious cycle of heightened stress, poor health choices, and spiraling physical consequences.
In my practice, over half of visits are for conditions that are either directly attributable to or worsened by stress. My experience is in line with national statistics: stress related illnesses may be a component of 60-80% of primary care office visits.
So how did our “flight-or-flight” stress response, which was evolutionarily designed to give us a survival advantage, become one of the greatest threats to our health?
The key is that we are programmed to use short term stress as a powerful emotion for performing our best. Stress hormones, most notably cortisol, ramp up so we can either stay and fight, or run. A short term stress response includes a relaxation phase, which gives stress hormones the chance to dial down.
Chronic or repeated stress is a modern phenomenon that forces our stress response to constantly be in the “on” position. Instead of confronting a bear, we are battling financial worries, family responsibilities, and job demands. When we don’t give our bodies the chance to dial down the stress response, we turn our lifesaving instinctive response into a hormonal cascade that paradoxically harms our body.
Although chronic stress can appear in many ways, here are some common physical signs I see in my practice.
High blood pressure
It’s a feeling we have all felt. You are about to give a presentation and your heart starts pounding out of your chest. The steps leading up to this have occurred in a split second. Your amygdala, the part of your brain that helps with emotional processing, has sent an alarm signal to your hypothalamus. Acting as command central, your hypothalamus has activated your autonomic nervous system to release adrenaline (also known as epinephrine) from your adrenal glands into your blood stream. As a result, your heart is pumping faster and your blood pressure spikes. Repeated stress eventually results in high blood pressure.
Heart attack and stroke
Besides indirectly increasing your odds of heart disease and stroke by raising your blood pressure, persistent stress may directly increase your risk by raising the level of pro-inflammatory chemicals in the body called cytokines. Inflammation can, in turn, damage the lining of your blood vessels. Scientists now know that this is an early step in triggering the process of atherosclerosis, or cholesterol plaque buildup in your arteries.
Call it your body being smart. When you are constantly under stress, your body tries to fuel up to prepare for the next challenge. After releasing adrenaline, the second part of your stress response, the hypothalamus-pituitary-adrenal (HPA) axis, triggers the adrenal glands to secrete cortisol. A.k.a. the stress hormone, cortisol not only keeps your stress response activated but also increases your appetite. Worse yet, it tells your body to replenish your energy stores with energy dense foods and carbs—the love-hate “comfort foods.” Only problem is that there is no bear. No fleeing. And the extra munchies to push through the hours behind your desk can make you pack on the pounds.
During the stress response, your body taps into your fat cells as another source of energy. Triglyceride are released into your blood stream, and if unutilized, redistributed as belly fat.
Along with cortisol, scientists believe neuropeptide Y (NPY), a neurotransmitter that regulates energy storage, may be the belly fat culprits. Under stress, NPY sends signals to the abdomen to store belly fat. Possible reason being that deep belly, or visceral fat is more easily converted to energy than fat in the thighs and buttocks. Accumulating deep belly fat, however, is dangerous. Visceral fat is capable of releasing hormones that add to inflammation and the risk of chronic diseases such as heart disease and diabetes.
Insulin resistance and diabetes
Insulin is a hormone that is in a tug of war with cortisol. Insulin helps muscle cells absorb glucose from bloodstream and helps fat cells store energy. Cortisol does the opposite. It obtains quick energy for your body during stress. Under chronic stress, cortisol thwarts the action of insulin, and renders cells insulin resistant. Insulin resistance leads to higher circulating blood sugar and diabetes mellitus.
Acid reflux and ulcers
The brain and the gut are intimately connected. The gut contains its own nervous system, or “little brain,” which communicates with the brain via the autonomic nervous system and hypothalamus-pituitary-adrenal (HPA) axis. Stress increases sensitivity to acid reflux. So even if the amount of acid you reflux isn’t changed, you are more likely to feel heartburn. Whether stress plays a role in developing ulcers is controversial. Even though the bacteria, Helicobacter Pylori, and non-steroidal anti-inflammatory pain relieving drugs are the most important causes of ulcers, chronic stress may contribute by interfering with your defenses against acid damage.
Immune system dysfunction
Confronted by stress, your immune system gets called into action. Immune cells prepare to fight invaders, and to heal in case of injury. Chronic stress continues to release the inflammatory cells needed in the healing process. Over the long term, this increases the body wide inflammation that can harm your health. Cortisol tries to tone down the immune response. Yet it does so at the expense of increasing susceptibility to infections such as the common cold.
The hippocampus, a brain region important for memory, is one of the parts of the brain that is most vulnerable to stress. In striking animal studies, chronic stress can cause the hippocampus to lose neurons, or nerve cells, and shrink. It can also alter its communicating pathways, or synapses. These changes may compromise your ability to learn and remember. Chronic stress can also accelerate memory decline and cognitive impairment leading to Alzheimer’s dementia.
Anxiety, aggression, and mental illness
Numerous studies have shown a correlation between chronic stress and development of mood disorders. How this happens isn’t exactly clear. Chronic stress can enlarge the amygdala, the brain region involved in fear, anxiety, and aggression. Animal studies also show that chronic stress can change connection pathways in the brain. A stronger pathway to your fear center could be behind a heightened fear response. And a weaker pathway to your decision making may explain impulsive behavior.
Shorten your life
Besides increasing your risk for developing diseases that cut years from your life, chronic stress can directly reduce longevity by damaging critical parts of your DNA called telomeres. Telomeres are stretches of DNA that cap chromosomes. They are often compared to tips of a shoelace because they protect DNA from losing shape or getting damaged. Each time a cell divides, telomeres shorten. When telomeres become too short, a cell can no longer divide, and hence dies.
People who live with chronic stress have been found to have shorter telomeres. A 2004 study among women caring for a chronically ill child showed that those who felt the most stress had telomeres that were shorter on average by the equivalent of a decade of aging compared to mothers that felt the least stressed.
Your best plan for avoiding the health consequences of chronic stress is to periodically put the brakes on your stress response—such as through exercise, meditation, laughter, or spending time with family and friends. In this way, you can take advantage of the short term boost you can get from stress without accumulating the damage of chronically released stress hormones.