What is stress?
Stress is your body's response to outside pressures or demands, called stressors. Your body responds to stressors by releasing chemicals and hormones into your blood, causing your heart to beat faster, your blood pressure to rise, and your muscles to tense. This physical response gives you more energy and strength to deal with the stressor. Once the stressor disappears or you have adapted to it, the body usually goes back to normal. However, extreme stress or stress over long periods of time (called chronic stress) can damage your emotional and physical health. Common symptoms of chronic stress include trouble sleeping, tiredness, headaches, backaches, upset stomach, irritability, and depression.
How does stress affect my stroke risk?
Stress is associated with high blood pressure and atherosclerosis, both strong risk factors for stroke. People who experience more stress and are less able to cope with it emotionally and physically are more at risk for stroke. One recent study of more than 20,000 people (57% were women) who had never had a stroke or heart disease found that stress was associated with an increased stroke risk, even after taking into account other stroke risk factors.1
Researchers are divided as to exactly how stress affects stroke risk, but there is evidence that stress can affect your stroke risk in two ways:
First, stress can affect your stroke risk by how you behave in response to stressful situations. Some people under stress tend to engage in unhealthy coping behavior that only makes the stress worse and can make them more sensitive to further stress. If you smoke or eat or drink too much in response to stress, you increase your risk of high blood pressure, heart disease, and stroke.
Second, stress can affect your risk of stroke by how your body responds to stress. When your blood pressure rises in response to stress, your blood vessels expand to accommodate the increase in blood flow. Usually, once the stressful condition disappears or you have adapted to it, your blood pressure and blood vessels go back to normal. However, if the stress doesn't disappear (it's long-term or chronic) or happens repeatedly, the sudden spikes in blood pressure can damage your blood vessels,2 the same way as if you had persistent high blood pressure.
Repeated or long-lasting blood pressure spikes may result in blood vessel wall damage and atherosclerosis, which can cause a blocked-vessel (ischemic) stroke. A study of 254 postmenopausal women aged 50 to 60 found that strong elevations in blood pressure in response to stress may eventually impair the blood vessel wall's ability to expand.3 A 4-year study of 726 adults (59% were women) aged 59 to 71 found that high levels of anxiety for a long period of time may increase the hardening (atherosclerosis) of the carotid arteries in your neck.4
How someone's blood pressure reacts to stress varies from person to person. Studies have found that people who have above-average blood pressure spikes in response to stress may be at higher risk for stroke than those with less reactive blood pressures.5