Whether it is down to work pressure, money worries or relationship troubles, most of us experience stress at some point in our lives. In fact, around 75% of us report experiencing moderate to high levels of stress over the past month. It is well known that stress can cause sleep problems, headache and raise the risk of depression. But in this Spotlight, we look at some of the more surprising ways in which stress may harm our health.
The National Institute of Mental Health (NIMH) define stress as the "brain's response to any demand." In other words, it is how the brain reacts to certain situations or events.
It is important to note that not all stress is negative. Many of us who have been in a pressurized situation may have found that stress has pushed us to perform better. This is down to a "fight-or-flight" response, whereby the brain identifies a real threat and quickly releases hormones that encourage us to protect ourselves from perceived harm.
It is when this fight-or-flight response overreacts that problems arise, and this usually happens when we find ourselves exposed to constant threats.
"Stress is caused by the loss or threat of loss of the personal, social and material resources that are primary to us. So, threat to self, threat to self-esteem, threat to income, threat to employment and threat to our family or our health," Stevan Hobfoll, PhD, the Judd and Marjorie Weinberg presidential professor and chair at Rush University Medical Center in Chicago, IL, and member of the American Psychological Association (APA), told Medical News Today.
Stress levels 'too high' in Americans
In February last year, the APA released their annual "Stress in America" Survey, which assesses the attitudes and perceptions of stress and identifies its primary causes among the general public.
The survey, completed by 3,068 adults in the US during August 2014, revealed that the primary cause of stress among Americans is money, with 72% of respondents reporting feeling stressed about finances at some point over the past month. Of these, 22% said they had felt "extreme stress" in the past month as a result of money worries.
The second most common cause of stress among Americans was found to be work, followed by the economy, family responsibilities and personal health concerns.
On a positive note, average stress levels among Americans have decreased since 2007. On a 10-point scale, respondents rated their stress levels as 4.9, compared with 6.2 in 2007. However, the APA say such levels remain significantly higher than the 3.7 stress rating we consider to be healthy.
"[Last] year's survey continues to reinforce the idea that we are living with a level of stress that we consider too high," says Norman B. Anderson, CEO and executive vice president of the APA, adding:
"All Americans, and particularly those groups that are most affected by stress - which include women, younger adults and those with lower incomes - need to address this issue sooner than later in order to better their health and well-being."
The surprising health implications of stress
"Stress is significantly associated with virtually all the major areas of disease," Prof. Hobfoll told MNT. "Stress is seldom the root cause of disease, but rather interacts with our genetics and our state of our bodies in ways that accelerate disease."
Some of the more well-known implications of stress that many of you may have experienced include sleep deprivation, headache, anxiety and depression. But increasingly, researchers are uncovering more and more ways in which stress can harm our health.
According to the American Heart Association (AHA), stress can influence behaviors that have negative implications for heart health.
Have you ever arrived home after a stressful day at work and reached for that bottle of wine? Many of us have.
In January 2015, MNT reported on a study that found working long hours was associated with risky alcohol use, which the study researchers say is partly down to the belief that "alcohol use alleviates stress that is caused by work pressure and working conditions."
Some of us may smoke in response to stress, while others may "comfort eat," which can lead to obesity. All of these are factors that can contribute to poor heart health by raising blood pressure and causing damage to the walls of the arteries.
According to a study reported by MNT in November 2014, stress may also reduce blood flow to the heart - particularly for women. The study researchers found that in patients with coronary heart disease, stressed women had a three times greater reduction in blood flow than stressed men.
Stress has also been associated with increased risk of heart attack. In 2012, a study published in The Lancet found that work stress may raise the risk of heart attack by 23%. And in February last year, MNT reported on a study by researchers from the University of Sydney in Australia, which found periods of intense anger or anxiety may raise heart attack risk by more than nine times.
Even after a heart attack, stress may continue to affect health. A study published in the journal Circulation in February 2015 found women were more likely to experience higher levels of mental stress following a heart attack, which results in poorer recovery.
You may be surprised to learn that stress has been associated with increased risk of diabetes. In January last year, a study published in JAMA Psychiatry found that women with symptoms of post-traumatic stress disorder (PTSD) - a condition triggered by very distressing events - were more likely to develop the condition than those without PTSD.
Periods of stress increase production of the hormone cortisol, which can increase the amount of glucose in the blood - a potential explanation for why stress has been linked to higher risk of diabetes.
For people who already have diabetes, stress can lead to poorer management of the condition. As well as interfering with stress hormones and increasing blood glucose levels, the American Diabetes Association note that stressed patients with diabetes may be less likely to take care of themselves.
"They may drink more alcohol or exercise less. They may forget, or not have time, to check their glucose levels or plan good meals," states the organization.
Alzheimer's disease affects more than 5 million people in the US and is the sixth leading cause of death in the country.
While the exact causes of the condition are unclear, past studies have suggested that stress may contribute to its development.
In March 2013, MNT reported on a study by researchers from the University of Gothenburg in Sweden, which found high levels of stress hormones in the brains of mice were associated with larger amounts of beta-amyloid plaques - proteins believed to play a role in Alzheimer's.
Another study published in 2010 by Finnish researchers found that women who had either high blood pressure or higher cortisol levels - both symptoms of stress - were more than three times as likely to develop Alzheimer's, compared with patients who did not have these symptoms.
More recently, a study published in The American Journal of Geriatric Psychiatry found that for seniors with mild cognitive impairment, anxiety could speed up progression toward Alzheimer's.
In 2012, the UK's Alzheimer's Society revealed they are embarking on a 3-year project to find out more about the association between stress and Alzheimer's disease.
"All of us go through stressful events. We are looking to understand how these may become a risk factor for the development of Alzheimer's," said lead investigator of the project Prof. Clive Holmes, of the University of Southampton in the UK.
Approximately 1 in 8 couples in the US have problems getting pregnant or sustaining a pregnancy. Increasingly, researchers are suggesting stress may be a contributing factor.
In May 2014, we reported on a study published in the journal Fertility and Sterility that found stress in men can lead to reduced sperm and semen quality, which may negatively affect fertility.
The researchers behind that study, including first author Teresa Janevic, PhD, an assistant professor at Rutgers School of Public Health in Piscataway, NJ, hypothesize that stress could trigger the release of glucocorticoids - steroid hormones that affect the metabolism of carbohydrates, fats and proteins. This could lower testosterone levels and sperm production in men.
"Stress has long been identified as having an influence on health," says Janevic. "Our research suggests that men's reproductive health may also be affected by their social environment."
And women may not be free from the effects of stress on fertility. In 2014, a study led by researchers from Ohio State University found that women with high levels of a stress-related enzyme in their saliva - alpha-amylase - were 29% less likely to become pregnant than women with low levels of this enzyme. What is more, these women were also more than twice as likely to be infertile.
How can you protect against stress-induced health problems?
Of course, the best way to reduce the risk of stress-related health implications is to tackle the stress itself.
In order to do this, you first need to recognize the symptoms of stress. Though these vary in each individual, they commonly include difficulty sleeping, fatigue, overeating or undereating and feelings of depression, anger or irritability. You may also be smoking or drinking more in an attempt to manage stress, and some people many even engage in drug abuse.
According to the NIMH, one of the best ways to tackle stress is to seek support from others, be it friends, family or religious organizations. If an individual feels they are unable to cope with stress, are having suicidal thoughts or has engaged in drug or alcohol use to try and manage stress, the organization recommends they seek help from a qualified mental health provider.
Exercise can also be an effective aid for stress. The Mayo Clinic explain that physical activity increases production of "feel-good" neurotransmitters in the brain, called endorphins. Exercise has also been associated with reduced symptoms of depression, as well as improved sleep quality.
The AHA provide some other ways to help deal with stress:
- Positive self-talk: turn negative thoughts into positive ones. Instead of saying "I can't do this," say "I'll do the best I can." Negative self-talk increases stress levels
- Emergency stress stoppers: if you start to feel stressed, count to 10 before you talk, take a few deep breaths or go for a walk
- Finding pleasure: engaging in activities you enjoy is a great way to stave off stress. Take up a hobby, watch a movie or have a meal with friends
- Daily relaxation: engage in some relaxation techniques. Meditation, yoga and tai chi have all been shown to reduce stress levels.
Our Knowledge Center article - "What is stress? How to deal with stress" - looks at some other ways of coping with stress.