April 23, 2013
By Michael Craig Miller
By Michael Craig Miller, M.D.
Harvard Medical School
We have been through some stressful months and years in the United States. A tough economy. Two wars. Mass shootings. And now, here in Boston, a bombing that took lives and caused devastating injuries. All capped by a tense manhunt that paralyzed the city.
According to an American Psychological Association survey:
- Almost 4 out of 5 Americans believe their stress level is either rising or staying the same.
- One in 5 report high levels of stress (rating their stress level as 8 or more on a 10-point scale).
- About 6 out of 10 adults say they're trying to reduce their stress.
Stress is unpleasant, even when it is temporary. It can trigger a cascade of stress hormones that leads to well-coordinated changes in the body. And it doesn't matter if the stress is environmental, such as a looming work deadline, or psychological, such as persistent worry about losing a job. When stress reactions become long-lasting, they can have negative effects on your health.
The Stress Response
Any stressful incident can make the heart pound and breathing quicken. Muscles tense and beads of sweat appear.
This combination of reactions is called the "fight-or-flight" response. It evolved as a survival mechanism so people could react quickly to life-threatening situations.
The hormonal changes and physiological responses that occur are carefully orchestrated — and nearly immediate. They help you fight off the threat or flee to safety. Unfortunately, the body can also overreact to stressors that are not life-threatening, such as traffic jams, work pressure and family difficulties.
Over time, repeated activation of the stress response takes a toll on the body. Research suggests that prolonged stress contributes to high blood pressure, promotes the formation of artery-clogging deposits, and causes brain changes that may contribute to anxiety, depression and addiction. More preliminary research suggests that chronic stress may also contribute to obesity, both through direct mechanisms (causing people to eat more) or indirectly (decreasing sleep and exercise).
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Your Natural Alarm System
The stress response begins in the brain and then spreads to the rest of the body. It's so efficient — and fast — that you're not aware of what's happening. That's why people are able to jump out of the path of an oncoming car even before they think about what they are doing.
When you confront an oncoming car or other danger, a distress signal is immediately sent to your hypothalamus (near the base of your brain).
The hypothalamus is a bit like a command center. This area of the brain communicates with the rest of the body to control breathing, blood pressure, heartbeat, and the dilation or constriction of key blood vessels and small airways in the lungs.
The hypothalamus sends signals to the adrenal glands. They, in turn, pump the hormone epinephrine (also known as adrenaline) into the bloodstream.
As epinephrine circulates through the body, several things happen.
- The heart beats faster than normal, pushing blood to the muscles, heart and other vital organs. Pulse rate and blood pressure go up.
- You start to breathe more rapidly. Small airways in the lungs open wide. This way, the lungs can take in as much oxygen as possible with each breath.
- Extra oxygen goes to the brain, increasing alertness. Sight, hearing and other senses become sharper.
- Meanwhile, epinephrine triggers the release of blood sugar (glucose) and fats from temporary storage sites in the body. These nutrients flood into the bloodstream, supplying energy to all parts of the body.
If the threat continues, the hypothalamus sends a signal to the pituitary gland. (The pituitary is not a part of the brain; it sits just below the brain, close to the hypothalamus.)
The pituitary releases a hormone that communicates with the adrenal glands. In turn, the adrenals release cortisol. Cortisol helps the body react to continued stress. When the threat passes, cortisol levels fall to put the "brakes" on the stress response.
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How To Lower Stress
Persistent stress can damage blood vessels and arteries, increasing blood pressure and raising risk of heart attacks or strokes.
If cortisol levels stay high, weight gain and fat build up occur. For example, cortisol increases appetite, so that people will want to eat more for extra energy. It also increases storage of unused nutrients as fat.
Fortunately, you can learn ways to counter the stress response.
- Relaxation. There are many techniques that work, including meditation, soothing visualizations, deep breathing and yoga. Research shows that these techniques are helpful for hypertension and various forms of heart disease. Many people feel better and enjoy using these methods, even if they may need to keep taking their blood pressure medication.
- Physical activity. Exercise, such as a brisk walk, can dampen stress in several ways. It deepens breathing and helps relieve muscle tension. Movement therapies such as yoga, tai chi and qi gong combine fluid movements with deep breathing and mental focus, all of which can induce calm.
- Social support. Social networks — confidants, friends, co-workers, family members — may increase longevity. It's not clear why, but people who enjoy close relationships get emotional support that indirectly helps them get through times of stress and crisis.
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Give Relaxation a Try
If the psychological survey is an indicator, you will have a lot of company in wanting to find ways to manage your stress. Stress management takes commitment. But the tools are there if you want to try them.
It helps to set aside a regular time for your relaxation practice. Also, instead of fiddling with your smartphone when waiting for an appointment or the train, for example, you could use the down time to practice.
And don't expect perfection. It's not a big deal if you miss a day, a week or even a month. Pull out these methods when it appeals to you to try again.
The good news is, the more you invest in these techniques, the more they'll repay you with an improved sense of well-being.
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Michael Craig Miller, M.D Michael Craig Miller, M.D., is Senior Editor of Mental Health Publishing at Harvard Health Publications. He is an assistant professor of psychiatry at Harvard Medical School. Dr. Miller is in clinical practice at Beth Israel Deaconess Medical Center, where he has been on staff for more than 25 years.