What triggers a stroke? The answer has been elusive, but a new study offers clues about what many survivors experienced soon before their stroke happened.
Anger or emotional upset was common in the hour before the onset of symptoms and was associated with all types of stroke, researchers wrote this month in the European Heart Journal.
Heavy physical exertion in the same time period was linked with increased odds of one type of stroke — intracerebral hemorrhage, or bleeding into the brain tissue.
“We believe that these triggering events may increase the heart rate, increase blood pressure and lead to hormonal changes that alter blood flows in vascular beds, such as the brain, which may increase the risk of stroke,” Andrew Smyth, lead author and professor of clinical epidemiology at the National University of Ireland, Galway, told TODAY.
“That being said, not every episode of anger or emotional upset or heavy physical exertion leads to a stroke. Similarly, not every individual who has a high burden of cardiovascular risk factors will have a stroke.”
A stroke happens when blood flow to the brain is suddenly interrupted, most often by a blood clot or other blockage. Oxygen-starved brain cells can be damaged or die in minutes, with devastating results.
Anyone can have a stroke at any age. TODAY contributor Bobbie Thomas' late husband suffered one at age 40. Children can be impacted, too.
It’s a leading cause of death in the U.S. and a major cause of serious disability for adults, affecting 795,000 Americans each year, the Centers for Disease Control and Prevention warned. Strokes are difficult to predict because they happen so suddenly and without warning signs.
Risk factors over the long-term include smoking, high blood pressure, atrial fibrillation, previous angina or heart attack. But the association with the more immediate triggers in this study was seen in people with and without those risk factors, Smyth said.
He and his colleagues analyzed 13,462 cases of first stroke in 32 countries. The patients were asked about their demographics, health history and what they had experienced before their stroke.
It turned out 1 in 11 survivors were angry or upset in the one hour leading up to it, with researchers linking it to a 30% increase in risk of stroke within 60 minutes after an episode.
“It’s definitely something that I’ve heard from patients before where they say, ‘I was just in this argument or got very upset and then this happened all of a sudden,’” said Dr. Amy Guzik, a neurologist and director of the Comprehensive Stroke Center at Wake Forest Baptist Health in Winston-Salem, North Carolina. She was not involved in the study.
One in 20 patients reported engaging in heavy physical exertion in the one hour before their symptoms. This would be activity over and above what would be usual for them — perhaps a longer run than they were used to, Smyth said.
It was linked to a 60% increase in risk of intracerebral hemorrhage — a less common type of stroke that happens when an artery in the brain leaks blood — within 60 minutes of the big effort.
Both anger and exertion can lead to a rapid increase in blood pressure, and that spike, especially if it’s not something a person is used to, can increase the risk, perhaps pushing an already weak blood vessel to tear, Guzik noted.
“There are definitely components of stroke risk that we know less about,” she said. “But I still think that the majority of stroke risk comes from known risk factors.”
They include high blood pressure, high cholesterol, family history, obesity, unhealthy diet, inactivity, smoking and too much alcohol.
Managing the triggers
Regular exercise is important for brain and cardiovascular health, but it’s best to avoid extremes of exertion, both experts said.
For people who’d like to boost their level of exercise, Smyth suggested a gradual increase in the intensity or duration rather than big sudden increases.
When it comes to mental health, it’s not possible to completely avoid episodes of anger or upset, so the focus should be on minimizing your exposure to distressing situations and reducing the stress on the body when they do happen, Smyth said.
The first step is taking a few deep breaths — Guzik recommended focusing on the exhale to regroup. There are many breathing exercises to calm down anxiety.
Consider taking a walk or taking some time alone to put some space between yourself and the emotionally charged moment, she said.
Meditation, mindfulness and regular exercise are all strategies for longer-term management of anger and upset, both experts noted.
Don’t forget to manage the risk factors you can control, like diet and hypertension.
“We look for total health to help prevent stroke. It’s all intertwined,” Guzik added.