Can You Have a Stroke in Your Sleep?

A stroke is a medical emergency that requires immediate treatment. Unfortunately, strokes can occur at any time, including when you are asleep. It's possible to wake up with stroke symptoms as a result of a stroke that happened while you were asleep. These are sometimes called "wake-up strokes."

Wake-up strokes are not technically different from other strokes. However, they can be more dangerous because treatment is delayed while you are sleeping.

This article discusses wake-up strokes, including risk factors associated with strokes during sleep.

What to Know About Wake-Up Stroke - Illustration by Katie Kerpel

Verywell / Katie Kerpel

What Is a Wake-Up Stroke?

A wake-up stroke is a stroke that occurs during sleep. In these cases, the person goes to bed feeling normal but wakes up with symptoms of a stroke.

Unfortunately, because the person has been asleep, it's unclear when the stroke occurred. This is an important factor, because the time of stroke onset is unknown, and strokes need to be treated as soon as possible.

Prevalence of Wake-Up Strokes

It's estimated that anywhere between 8% and 28% of all strokes occur during sleep.

Causes and Risk Factors

A stroke is caused by a disruption in blood flow to the brain. This can be either a blockage (called an ischemic stroke) or blood leaking (called a hemorrhagic stroke).

There are many well-known risk factors for stroke, including:

Although a wake-up stroke is generally considered to have the same cause and mechanism as other occurrences of stroke, researchers have identified a few factors that might put you at greater risk of having a wake-up stroke compared to a stroke while you are awake.

Age

The risk of having a stroke increases the older you get. But there is minimal evidence on how age relates to risk of a wake-up stroke.

In one study, regarded as the highest-quality population study of wake-up strokes to date, the average age of wake-up stroke was 72, compared to 70 for other occurrences of stroke.

However, in another study with a much smaller sample group, wake-up stroke survivors were significantly younger than those who had strokes while awake.

Sleep Disorders

The role of sleep disorders in causing or increasing the risk of wake-up stroke is not well understood, but it is an active area of research.

A 2020 study found that obstructive sleep apnea is a risk factor for strokes, but it is not more or less associated with wake-up strokes than non-wake-up strokes.

Cause and Effect

Obstructive sleep apnea and other sleep disorders are a risk factor of stroke, but they can also be caused by strokes.

One study found that those who had wake-up strokes were more likely to snore (90.5%) than those who had strokes while awake (70%).

Lipid Profile

High cholesterol is a risk factor for stroke. Some research indicates that wake-up stroke survivors have a significantly worse lipid profile than non-wake-up stroke survivors.

Blood Pressure

Hypertension (high blood pressure) is a risk factor for strokes in general. Research has found that hypertension is associated with an increased chance of cerebral infarction strokes during sleep.

Smoking

Smoking increases your chance of having a stroke. In particular, smoking may increase the risk of having an intracerebral hemorrhage, a type of stroke during sleep.

Signs and Symptoms of a Stroke

The signs and symptoms of a wake-up stroke are the same as strokes that occur during the day. The only difference is that these symptoms are not noticed until the person wakes up.

Symptoms of stroke include:

  • Facial drooping, often only on one side
  • Arm or leg weakness
  • Speech difficulties
  • Dizziness
  • Vision disturbances
  • Confusion
  • Incontinence (inability to control urine)

For example, a person who is having a wake-up stroke might find they have vision loss when they open their eyes in the morning. They may have wet the bed during the night, or they might find their arm too limp to remove their bed covers and sit up in bed.

It's essential to call 911 immediately if you notice the signs of stroke in yourself or someone else.

How Wake-Up Strokes Are Treated

There are some things to be aware of when treating a wake-up stroke, compared to a stroke with a known time of onset.

Because the time of stroke onset is unknown, wake-up stroke survivors are often ineligible for treatment with reperfusion therapy with tissue-plasminogen activator (tPA). This is a highly effective treatment to restore blood flow to the brain through blocked arteries, but it must be initiated within 4.5 hours of stroke.

Because people with wake-up stroke cannot take advantage of tPA, their outcomes may be poorer.

Diagnostic neuroimaging, such as CT scans and MRIs, are therefore an important part of wake-up stroke treatment. Increasingly, experts have been urging the use of neuroimaging to help identify the time of stroke onset in order to include more wake-up stroke survivors in reperfusion treatment.

After the person is medically stable, treatment for wake-up stroke is similar to treatment for any other type of stroke. Physical therapy, occupational therapy, and speech therapy should begin within 24 hours and continue intensively with a patient-centered plan.

Recovery and Outcomes

Recovery and outcomes for wake-up strokes follow a similar pattern as other strokes. The location in the brain and the extent of damage from a wake-up stroke, as well as other factors like co-occurring medical conditions, will all affect your recovery process.

According to some studies, there is no difference in clinical features or outcomes between wake-up strokes and other strokes.

Other research indicates people who had wake-up strokes are more severely affected, but there is no difference in fatality. This could be due to delayed time between onset and treatment, and exclusion from certain treatments like reperfusion.

Resulting Sleep Disorders

Some people who have had a stroke develop a stroke-induced sleep disorder. About two thirds of stroke survivors will develop sleep disordered breathing.

Summary

Wake-up strokes occur when a person goes to bed feeling normal and wakes up with symptoms of a stroke. The key difference between wake-up strokes and other types of stroke is that the time of onset is unknown. This can delay emergency medical treatment and exclude wake-up stroke survivors from typical stroke treatments.

A Word From Verywell

There is still a lot to learn about wake-up strokes and how they differ from strokes that occur when people are awake. What is known is that wake-up strokes are not uncommon. If you wake up and are experiencing weakness, vision loss, dizziness, incontinence, or confusion, it's important to seek medical attention as soon as possible.

Frequently Asked Questions

  • Can you have a stroke and not know it?

    Yes, it is possible to have a stroke and not know it. Usually, this is a TIA (also called a ministroke), and evidence may be discovered with neuroimaging at a later date.

  • How common are strokes during sleep?

    An estimated 8%–28% of strokes occur during sleep.

  • What happens if a ministroke goes untreated?

    Having a ministroke puts you at greater risk of having a full stroke in the future. The danger of having a ministroke that is not treated is that you don't receive the medical treatment, therapy, and education to help you change your modifiable risk factors to lower your risk of another stroke.

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7 Sources
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