Roberta Lee, MD, vice chair of the Department of Integrative Medicine at Beth Israel Medical Center in New York City, calls the now-common condition of constant pressure “superstress.” In her book The Superstress Solution, she lists the variety of stressors many now take for granted: job dissatisfaction, overwork, inadequate salaries, not enough time with partners and family, noise pollution, lack of outdoor time, and “spiritual angst” prompted by a loss of meaning and purpose, as well as a loss of connection with others.

As Henry Emmons, MD, of the Penny George Institute for Health and Healing in Minneapolis, points out, “your body can’t differentiate between a saber-toothed tiger attack and a bad job review.” The nerve-and-hormone response is the same. And over time, the intensity of the stress response wears a body down.

Lee compares the effects of a near-constant cascade of stress hormones to revving an auto engine all day. “You’ve got your foot on the accelerator all the time, even when you’re resting,” she says, “and you’re overutilizing every element of your body, like you do with a car when you’re revving up an engine. You overuse the oil. You increase heat.”

Here’s what happens to our organs and biochemistry when we’re stressed out . . . 

The Brain
The stress response begins above your shoulders. The amygdala (a cluster of cell nuclei inside the temporal lobe that processes emotional data) sends a threat message to the hypothalamus, which in turn tells the sympathetic nervous system to protect you from attack. The nervous system increases heart rate, constricts some blood vessels and dilates others, slows down the intestines, inhibits digestive secretions, and prompts glands to flood the system with cortisol.

If this alarm is set off too often, it can do serious physical damage. “When too much cortisol is hitting the brain for an elevated amount of time,” Lucille says, “you start to create something called hippocampal brain damage, and the results of this are disturbed circadian rhythms: Your sleep-wake cycle is disturbed. You get moody, and you get memory loss, brain fog.”

The Pituitary Gland
Sometimes called the “master gland,” the pituitary controls most of the other glands in the body, regulating a host of functions including body temperature, thyroid activity and urine production (hence those sweaty palms and frequent bathroom trips when you’re nervous). During the stress response, the pituitary produces adrenocorticotropic hormone (ACTH), which prompts the adrenal glands to produce cortisol. Cortisol increases arterial blood pressure, pulling glucose and fat from body tissues into the bloodstream for energy, one reason appetite diminishes during acute stress.

The pituitary gland also releases thyroid-stimulating hormone, which stimulates the thyroid gland to produce thyroxine. Thyroxine increases the metabolic rate, raises blood-sugar levels, and increases respiration, heart rate and blood pressure — all essential to a quick burst of activity. But the metabolic boost from thyroxine uses up nutrients too quickly, so the body overuses B vitamins and excretes calming magnesium.

The Heart
Blood vessels constrict during the stress response, which makes it harder for the heart to pump blood. High blood pressure from constricted vessels and increased cortisol and thyroxine only exacerbates inflammation and arterial plaque buildup.

Additionally, fatty acids released into the bloodstream by cortisol can lead to overproduction of low-density cholesterol (LDL).

High-density cholesterol, or HDL, actually helps keep the circulatory system functioning and has powerful healing value. But, notes Lee, the so-called bad version, LDL, contributes to dangerous plaque buildup on arterial walls that have been inflamed by toxins and high blood sugar — common byproducts of stress eating.

And all this sets the stage for cardiac arrest, says Lee.

Adrenal glands
Upon detecting a threat, the hypothalamus signals the adrenal medulla (an autonomic-nervous-system node next to the adrenal glands) to secrete two hormones — adrenaline and noradrenaline — into the bloodstream. These increase heart rate and blood pressure. Blood is pumped to extremities and their muscles to help you run or go into battle, while gastrointestinal activity is reduced, producing the feeling of butterflies in the stomach. When this complex process is repeated routinely with no time for recuperation, you start to feel both lethargic and wound up — tired but wired.

Chronic stress also wears out the adrenal glands by overusing their store of energizing adrenaline. According to Lee, this can lead to a condition that integrative and naturopathic doctors identify as “adrenal fatigue,” which can manifest as exhaustion, physical weakness, immune suppression, hormone imbalances, skin problems and depression. 

Stomach and Intestines
The slowdown of the digestive process triggered by the sympathetic nervous system and the thyroid can prompt either overproduction or underproduction of digestive acids. Overproduction can lead to painful acid reflux (heartburn), while underproduction means your stomach has limited digestive power. Too little stomach acid can leave food in the system so long that it ferments rather than digests. This can produce bloating, create inflammation of the intestinal tissue and reduce the overall absorption of nutrients.

“If your bowel’s inflamed,” says Emmons, “you’re not getting nutrients out of the food you eat. You can eat really great food but still not benefit from it.”

Body Fat
While some people do lose weight under stress, research reveals that high levels of cortisol can also encourage weight gain in two ways:

(1) Cortisol amps up the appetite for quick energy (namely, carbohydrates and sugar), triggering cravings and overeating. (2) Cortisol also puts excess glucose in the bloodstream. When it’s not burned off through exercise (the equivalent of sprinting away from or fighting off the perceived attacker), it gets stored as fat in your body’s tissues.

That makes chronic stress a real enemy of overall fitness, Emmons points out. “You tend to gain weight because cortisol is making you want to eat more. But it’s also making you more likely to hold on to that food as fat, especially as abdominal fat.”

Reproductive system
Progesterone is a crucial hormone for fertility in women; it nourishes the lining of the uterus to support the implantation of an embryo and sustain a pregnancy. It’s also a key ingredient in the creation of cortisol in the adrenal glands. When the body demands large amounts of cortisol, its total amount of progesterone can diminish, leading to low libido and possible infertility. (For more details about how stress affects your romantic and reproductive life

The Aging Process
In 2004 a University of California, San Francisco research team reported that chronic stress may play a role in shortening telomeres, the tiny protein complexes at the ends of chromosomes that help protect genetic information as cells divide. As telomeres shorten, cells lose the ability to divide; they can also get confused about their mission and start to manifest serious ailments, from Parkinson’s to heart disease. (Other studies have linked shortened telomeres with the onset of dementia.) While cell loss is an integral part of the aging process, chronic stress accelerates it by munching away at these protective proteins so they diminish faster than they would naturally.