You probably already know that stress isn’t healthy for you. But, you might not know why or what you can do about it. February is American Heart Month, so we’re going to take a look at the effects of stress on the heart.
According to the Centers of Disease Control and Prevention, heart disease is the leading cause of death in the United States, accounting for almost one-third of all deaths per year. Deaths from cardio-vascular disease (disease of the heart and blood vessels) are caused both by problems that happen quickly and unexpectedly, as well illnesses that develop over time.
Stress has been implicated in contributing to both kinds of heart disease: death is more frequent in the month following the death of a loved one, and the number of heart-related illnesses rises after natural disasters. There is also a peak in the number of people who die of heart-related causes around Christmas and New Years (a socially stressful time of the year). Lastly, combat veterans with symptoms of the anxiety illness Post Traumatic Stress Disease (PTSD) have more heart disease.
• What is stress?
Stress is what happens to us when we’re exposed to a threatening situation. A threat is anything we believe may have a negative impact in our lives. Basically there are two kinds of stress: acute, stress that happens quickly and then ends; and chronic, stress that goes on over a long period of time. Each of these kinds of stress affects the body differently. We’ll begin with acute stress.
Let’s say you’re out walking, calmly listening to music. You start to cross the street, but suddenly you see a car that isn’t stopping. You hear the screech of the brakes. You feel a jolt of anxiety and dart out of the way. When you get to the other side you’re breathing quickly and you feel your heart pounding in your chest. A few moments later you regain your composure. Your heart and breathing slow to their normal rate and, especially if you live in New York where this happens often enough, you go about your business without a second thought.
So what just happened inside of you? Your brain perceived a threat to your life which caused your body to go through physical changes. These changes happened automatically. You did not need to stop and think. Your senses (eyes, ears) set your brain in motion. It sent signals to the rest of your body to enable it to move quickly. You became more alert. Special nerve pathways that lead from your brain to the rest of your body’s main organs, turned up your heart rate, increased your blood pressure, opened up your lung passages, so you could take in more oxygen, and sent more blood to your legs so that you could run faster.
The stress hormones (chemical messengers) adrenalin and cortisol were released. These hormones told the body to increase your blood sugar so that you heart, leg muscles and brain had more energy available to them. They also helped increase your heart rate and the strength at which it pumps. Normal body functions that weren’t needed at that moment were turned down including digestion and the immune system. Once the threat was over your brain stopped the alert and sent messages to put your body back to its normal balanced state.
There are a lot of situations in our lives where we feel threat and experience acute stress. Let’s say you are at work when all of a sudden you realize you’re late for a meeting (if you miss the meeting your boss will be angry); or your term paper is due in two hours and it isn’t finished just yet (if you don’t complete it you’ll get a bad grade). In each of these cases you get the jolt of the acute stress response which helps you to become more focused and move more quickly. You accomplish what you need to do, the threat passes, the stress response gets turned off and your body returns to its usual balanced state.
Most of the time such situations leave us no worse for wear, unfortunately, sometimes the acute stress response can injure the heart. Our brain can send over-active messages to the heart’s natural pacemakers and heart muscle, which cause faulty rhythms (arrhythmias). The heart muscle contracts irregularly and blood doesn’t get pumped out of it effectively (it just sloshes around). The rest of the body, most notably the brain, is deprived of fresh oxygen, which can lead to sudden death. These kinds of problems most often happen in people whose hearts already have some damage.
• The effects of chronic stress on the heart
Chronic stress can be caused by anything we find threatening in an ongoing basis, such as a difficult job, unpaid bills, a sick child, an elderly parent, or relationship problems. We can think ahead and can fear something that hasn’t happened (and may never happen.) We can also dig into our past for old problems and bring thoughts of them into the present. We can then take these worries and churn them around in our heads over and over again. In doing so we create a sense of threat and fear that doesn’t leave us. Our brain, not knowing the threat isn’t a predator about to kill us, activates the stress response and keeps it turned on.
Chronic stress causes heart disease through it’s affect on many areas of the body. When the heart stays revved up it pushes blood at high speed and pressure against the walls of the blood vessels (arteries). This causes them to get worn and in response, they thicken and narrow (kind of like muscular scar). Raised amounts of cortisol increase blood sugar (hyperglycemia) and can lead to diabetes. Cortisol also effects our processing of fat and cholesterol. Cholesterol (especially the LDL type) can form plaques. Plaques are areas where cells and cholesterol stick together against the inside of an artery. If the build-up gets large enough it can close off an artery, like gunk blocking a hose. Chronic stress also shifts the immune system out of balance. Chemicals are released that further injure artery walls and makes blood cells stickier. When clumps of sticky blood cells (clots) get wedged in a narrow artery they cause the artery to be blocked, cutting off the blood supply to that area of the body. If this happens in the brain it causes a stroke.
The heart has to do a lot more work to push blood through narrowed arteries. Blood pressure stays up (hypertension) and the heart muscle gets bigger. An enlarged heart needs a greater oxygen and energy supply. Even though the heart has all that blood passing through it, it needs blood vessels to feed the outer muscle (coronary arteries). But the coronary arteries like the other arteries in the body, can become damaged, clogged by plaque and then blocked by a clot. When this occurs, the heart muscle doesn’t get the oxygen it needs and areas of muscle can die. This is what happens in a heart attack (myocardial infarction -MI).
There are other ways that chronic stress can affect the heart. The chemical changes from chronic stress can cause depression and anxiety and both of these types of illness are associated with an increased risk of heart disease.
In addition to all of these changes that happen automatically, we can voluntarily make things worse. Typically, when we are under stress we smoke, drink, eat more, and spend less time exercising. All of these things can worsen the risk for high blood pressure, plaques, clots and add more stress on the heart.
OK. That was a lot of information. And perhaps now you are feeling hopeless. After all, your world is so full of stress you must be doomed.
Take comfort. This doesn’t just have to scare you. Now that you know what’s happening there are things you can do to keep your body healthy and repair existing damage.
• Things you can do
You can see your doctor to be evaluated for high blood pressure and diabetes and get treated if you have them. You can quit smoking (see my TIPS TO QUIT) eat healthier foods, go easy on the alcohol and increase your exercise. Exercise can help the stress system find its balance, help you lose weight, reduce your ‘bad’ (LDL) cholesterol, clear up your arteries, and reduce high blood pressure. All of which reduces the strain on your heart. If you have any risk factors, please consult your doctor before you exercise. Lastly, but perhaps most importantly, you can try to reduce the stressors in your life or change your approach to them.
In my Handling Stress article we’ll explore things we can do to take control over some of the stressors in our lives, and the importance of finding balance all of which can help us to protect our hearts.
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Dr. Elizabeth Getter received her undergraduate degree from Brown University and medical degree from the University of North Carolina at Chapel Hill. Dr. Getter has lectured on and worked extensively with the problem of addictions as well as the psychiatric problems of persons with HIV and AIDS. She is an Assistant Clinical Professor of Psychiatry & Behavioral Sciences at Albert Einstein College of Medicine of Yeshiva University and currently has a private practice in psychiatry in New York City.