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The #1 Cause of a "Silent Stroke"

Here’s what causes a stroke with no symptoms.
FACT CHECKED BY Emilia Paluszek

Silent strokes may be more common than people know. "A statement issued by the American Stroke Association and American Heart Association estimated that as many as a quarter of octogenarians may have experienced one or more strokes without symptoms," say Toni Golen, MD, and Hope Ricciotti, MD. "These events are often detected only when a person undergoes brain imaging for another reason. How is this possible? A silent stroke is most often caused by reduced blood flow in one of the smaller arteries that feed the brain. It can occur without noticeable symptoms if it affects a part of the brain that doesn't control major movements or vital functions." Here is what causes silent strokes—including the main reason. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


High Blood Pressure

doctor taking patient's blood pressure with analog device
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High blood pressure (hypertension) is strongly associated with a risk of silent strokes. "HBP adds to your heart's workload and damages your arteries and organs over time," says the American Stroke Association. "Compared to people whose blood pressure is normal, people with HBP are more likely to have a stroke. About 87% of strokes are caused by narrowed or clogged blood vessels in the brain that cut off the blood flow to brain cells. This is an ischemic stroke. High blood pressure causes damage to the inner lining of the blood vessels. This will narrow an artery."


Unhealthy Diet

Obese woman laying on sofa with smartphone eating chips

Eating a diet high in ultra processed junk food and sugar can increase the risk of silent stroke. "The common causes of stroke are still undertreated — and awareness of stroke risk factors is low," says Brett Cucchiara, MD, Professor of Neurology at Penn Medicine. "There are simple steps that people can take to drastically reduce their risk of having a stroke. A lot of people are surprised to know that how you eat can affect your risk for a stroke. There's good data showing that a Mediterranean-style diet can help reduce your risk."



overweight woman at home lying on the floor, laptop in front of her, prepared to work out on mat according to video

Obesity is strongly linked to stroke risk, doctors warn. "Basically, being obese seems to be a 'solo player' associated with heart injury—that is, regardless of high blood pressure, elevated cholesterol and diabetes," says Johns Hopkins cardiologist Chiadi Ndumele, MD, MHS. "Down the road, this can lead to heart failure. Lots of factors can cause heart failure, and the obesity epidemic is likely a contributor."


High Cholesterol

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High cholesterol can lead to silent stroke, experts say. "High cholesterol levels build up fatty plaques that reduce blood flow in the arteries—a condition called atherosclerosis, which can lead to a stroke," says Harvard Health. "If diet and exercise don't bring your cholesterol levels down far enough, your doctor may prescribe cholesterol-lowering drugs that can significantly cut your stroke risk."


#1 Cause Is Blood Flow Blockage

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The #1 cause of silent stroke is when blood flow to the brain is interrupted, something that can happen several times. "A blood vessel can get blocked off, the tissue supplied by that vessel can die, but the person doesn't experience symptoms so they don't know they've had a stroke," says Karen Furie MD, MPH, associate professor at Harvard Medical School and director of the Massachusetts General Hospital Stroke Service. "The more brain damage or injury that you have due to these silent strokes, the more difficult it is for the brain to function normally."

Heather Newgen
Heather Newgen has two decades of experience reporting and writing about health, fitness, entertainment and travel. Heather currently freelances for several publications. Read more about Heather
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