7 health dangers aggravated by stress

By John Murphy
Published June 11, 2020

Key Takeaways

One of the most dangerous causes of illness is invisible, intangible, and nearly immeasurable. It can strike unexpectedly and it can also accumulate over time. It’s simultaneously everywhere and nowhere, but it affects everyone. 

It’s stress, and it plays a part in up to 75% to 90% of human diseases, according to researchers. In one study that surveyed more than 200 physicians, 25% to 30% reported high chronic stress.

Stress is good when it helps you outmaneuver a charging bull or hurry away from a menacing figure in a dark alleyway. (What are you doing messing around in bullrings and going down dark alleys, anyhow?!) In such fight-or-flight predicaments, stress stimuli galvanize the body to respond in a physiological way. 

This response kicks off a horde of neurochemical, neurotransmitter, and hormonal changes by activating the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis. These systems fire off chemical mediators to protect the body. For instance, a surge of catecholamines cranks up heart rate and blood pressure, helping you to fight that bull or take flight from that menacing malefactor.

So far, so good. But, when stress is continuous, when it doesn’t let up or go away, then good stress (which has an actual name: eustress) drops out of the picture and bad stress (aka, distress) moves in. This bad, chronic stress can gradually wear the body down, causing or exacerbating common physical illnesses. 

In an MDLinx survey, 38% of doctors said that both stress and added workload contributed to the development or worsening of one or more of their chronic conditions, such as heart disease, diabetes, depression, and more. 

Cardiovascular disease

Chronic stress has long been associated with heart attack, not to mention hypertension, atherosclerosis, and cardiovascular mortality. Chronic stress is believed to compel the sympathetic nervous system to work overtime. This puts more catecholamines into the system, resulting in increased heart rate and blood pressure. Stress can also cause the release of cholesterol and triglycerides into the blood.

Inflammatory processes are also likely at work, as chronic stress appears to stimulate the sympathetic nervous system into releasing pro-inflammatory mediators that induce systemic inflammation. Chronic inflammation, of course, is the main cause or contributor to chronic diseases—notably, cardiovascular disease.


Chronic stress affects type 2 diabetes in at least a couple of ways. For many of us, we eat more indulgent or junk food as a way to appease stress. (Have you been affected by the “quarantine 19” or the “COVID-19”—the extra 19 lb gained from stay-at-home snacking?) Investigators have shown that stress eating predicts worse glycemic control, pre-diabetes, and diabetes—relationships that are mediated by waist circumference. Other researchers have found that chronic psychological stress, caused by stressful life events, is associated with higher prevalence of undetected type 2 diabetes.

Another way that stress affects type 2 diabetes: Periods of acute or chronic stress often precede insulin resistance. How? It’s likely that metabolism-controlling stress hormones induce anti-insulin effects, which bring about insulin resistance over time.


Stressful life events—such as the death of a family member, chronic illness, or a job loss—are linked to symptoms of depression and major depressive disorder. Approximately 20% to 25% of people who experience major stressful events develop depression. Increased stress also predicts that the clinical course of major depression will be longer in duration, with exacerbated symptoms and relapse.

Stress also promotes depression through other illnesses. As noted throughout this article, stress contributes to chronic conditions, like heart disease, diabetes, neurodegenerative disorders, and others. In turn, these chronic conditions themselves can increase the risk of depression, according to the National Institute of Mental Health.

Alzheimer disease

Scores of studies in animals have demonstrated that stress promotes the progression of Alzheimer disease. For example, researchers have shown that stress not only elevates the production of amyloid-beta, it also hastens the deposition of amyloid plaques—a hallmark feature of Alzheimer disease.

What’s the mechanism between stress and neurodegenerative disease? Chronic stress puts the hypothalamic-pituitary-adrenal axis into overdrive, which results in increased levels of the stress hormone cortisol in the system. Researchers have found that higher levels of circulating cortisol are linked to more rapidly advancing neurodegeneration.

To make matters worse, having Alzheimer disease is stressful in itself. This leads to a “vicious cycle of stress” in which stress produces neuropsychiatric complications that further accelerate disease progression.


Stress may contribute to cancer risk and, especially, disease progression. Research in animals has indicated that stress contributes to the formation, growth, and metastasis of certain tumors. In humans, researchers have learned that stress affects key pathogenic processes in cancer, such as antiviral defenses, DNA repair, and cellular aging.

Stress likely has a greater influence on the progression and recurrence of cancer than on the onset of the disease. While further research needs to be done to investigate this connection, the effects of stress appear to be more pronounced in cancers related to antiviral immunity and sustained activation of hormonal response, such as cervical cancer, hepatocarcinoma, and HIV-related tumors.


Stress affects sleep—a problem common to everyone at one point or another. But, for people who already have sleep troubles, stress can make things much worse. Stress may aggravate or perpetuate sleeplessness, making it especially difficult for people to get back to sleep when they wake up at night. This occurs because higher cortisol levels from stress can disturb sleep patterns. Making matters worse, sleep deprivation impairs memory and emotional control, so that people with troubled sleep at night have even more difficulty handling stress during the day.

Colds and infections

People under chronic stress may be more likely to get sick from infections. Psychological stress can block many of the immune response’s defenses, including innate immunity, T-cell responses, and antibody production.

In one study, researchers tested this by surveying healthy adults about their stress levels, and then deliberately infecting them with common respiratory viruses. Those who were more stressed got more sick.

“Psychological stress was associated in a dose-response manner with an increased risk of acute infectious respiratory illness,” the authors concluded.

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