Research suggests that the risk of a stroke is highest within 3 days of a COVID-19 diagnosis but can remain high for months. It’s thought that the inflammatory response to the virus that causes COVID-19 may play a role in increasing risk.

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Every 40 seconds, a person in the United States has a stroke, according to the Centers for Disease Control and Prevention (CDC). Most strokes, about 87%, are ischemic strokes, which occur when blood flow in the brain is blocked.

COVID-19 has been associated with an increased risk of stroke. In fact, your risk of stroke after having COVID-19 can remain elevated for months after you recover from your infection.

This article will take a closer look at what’s known about the link between COVID-19 and stroke risk.

COVID-19 is associated with a higher risk of stroke. Many of these strokes are ischemic strokes, although hemorrhagic strokes — caused by a ruptured blood vessel in the brain — have also been reported.

A 2022 study proposes the following mechanism as to how COVID-19 leads to an increased stroke risk:

  1. The virus that causes COVID-19 infects the cells that line the inside of the blood vessels, called endothelial cells.
  2. Infected cells release several pro-inflammatory factors that recruit other immune cells to the area.
  3. These immune cells also make inflammatory factors, which can eventually damage the endothelial cells.
  4. Damage to the endothelial cells can lead to the activation of platelets and other factors involved in clotting. This increases the risk of a blood clot that could travel to the brain and cause a stroke.

Additionally, another large study found that the risk of developing dangerous blood clots in the lungs or legs is significantly elevated for up to 6 months after having COVID-19.

So far, the research hasn’t determined why a blood clot develops in one location instead of another, and it may be related to underlying preexisting conditions. Also, the risk of blood clots seems to vary among COVID-19 strains.

The risk of stroke is highest right after COVID-19 diagnosis

Some research has found that the risk of stroke is highest in the days immediately after you become ill with COVID-19. A 2022 study identified 37,379 Medicare beneficiaries who had both COVID-19 and stroke diagnosed.

The study found that the risk of stroke was 10 times higher in the first 3 days after a COVID-19 diagnosis. This association was strongest in people ages 65 to 74 and in people who had no prior history of stroke.

The risk of stroke remains elevated months after you recover

An elevated stroke risk isn’t only present during the early stages of COVID-19. It may persist for months.

Another 2022 study used healthcare data from the Department of Veterans Affairs to compare people with COVID-19 with current and historical control groups. The goal was to estimate the risk of cardiovascular events in the 12 months after COVID-19.

The researchers found that people who had COVID-19 had a 53% higher risk of having a stroke or a transient ischemic attack (TIA) in the next 12 months.

While those who were hospitalized with COVID-19 or cared for in an intensive care unit (ICU) had a higher risk of stroke, individuals who weren’t hospitalized also had a slightly elevated risk of stroke or TIA.

Asymptomatic people may also have an increased risk of stroke

A 2021 case series of 18 people suggested an increased risk of stroke in people who tested positive for SARS-CoV-2 (the virus that causes COVID-19) but had no respiratory symptoms. The median time period from the positive test result to the stroke was 54 days.

The outcome of COVID-19-associated strokes can be poor

A 2022 study included 216 people with COVID-19 at 30 stroke centers in the United States and Canada. It found that 51.3% of stroke outcomes were poor and the mortality rate was 39.1%.

The following factors were associated with poorer stroke outcomes:

Stroke with COVID-19 is still uncommon

While people with COVID-19 are at a higher risk of stroke, it’s still an uncommon occurrence. A 2021 study that included 8,163 people hospitalized with COVID-19 across 54 healthcare facilities found a rate of stroke of 1.3%.

People who have risk factors for stroke are most likely to be affected. The research also found that stroke in people with COVID-19 often occurred in the presence of other risk factors that are already known to boost stroke risk. These risk factors include:

How to recognize the symptoms of a stroke

A stroke is a medical emergency that requires immediate care. Call 911 or local emergency services or go to the emergency room if you or someone else around you suddenly experiences:

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Whether or not you’ve had COVID-19, there are several factors that are known to increase your risk of stroke, including:

While not all strokes can be prevented, certain lifestyle choices can go a long way in lowering your risk of stroke. This includes:

The added benefit of these lifestyle choices is that they not only reduce your risk of stroke but can also boost your overall health.

COVID-19 can increase the risk of stroke, possibly through the inflammatory response to infection. Stroke risk can remain elevated for months after your recovery from COVID-19.

Several factors are known to increase your risk of stroke, including high blood pressure, diabetes, heart disease, and smoking. Making lifestyle changes may help lower your risk of a stroke.

A stroke is a medical emergency. If you or someone around you has symptoms of a stroke, call 911 or local emergency services immediately or get to the nearest emergency room.