Having high blood pressure, or hypertension, can increase a person’s risk of having a stroke. A reading of 180/120 millimeters of mercury (mmHg) or greater requires immediate medical attention.

Blood pressure relates to the amount of force with which blood pushes against the walls of the arteries. Therefore, increases in pressure can damage the blood vessels. When there is damage to the vessels or bleeding in the brain, it can lead to strokes.

Managing blood pressure is an important step for someone to take to help reduce stroke risk.

Read on to learn how high blood pressure might relate to stroke risk. This article also explores the steps someone can take to reduce the risk of strokes or recurrent strokes.

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The American Stroke Association states that high blood pressure is a major risk for stroke. The organization defines the different stages of high blood pressure as below.

The systolic number represents the blood pressure in the arteries when the heart beats. At the same time, the diastolic number represents the blood pressure in the arteries when the heart rests between beats.

Blood pressure categorySystolic (mm Hg): Upper numberDiastolic (mm Hg): Lower number
Hypertension stage 1: High blood pressure130–139or80–89
Hypertension stage 2: High blood pressure140 or higheror90 or higher
Hypertensive crisishigher than 180 and/orhigher than 120

A person should call 911 if they notice someone might be experiencing a hypertensive crisis.

An elevation in blood pressure can directly affect the brain. Additionally, high blood pressure can increase a person’s risk of having a stroke due to bleeding in the brain.

Different types of stroke can occur due to the changes that high blood pressure cause. This can include:

  • Ischemic stroke: Blood vessels can become narrower and stiffer, causing fatty plaque buildup inside the vessels — doctors call this atherosclerosis. Clots can form on the fatty plaques, travel to the brain, and lead to stroke or a transient ischemic attack, or mini-stroke.
  • Hemorrhagic stroke: Damage to blood vessels in the brain can result in bleeding.
  • Small vessel disease: Damage to the tiny blood vessels deep inside the brain can increase a person’s risk of stroke. It can also affect their cognitive function.

The Centers for Disease Control and Prevention (CDC) list the following signs to look for, and some of these may appear suddenly:

  • numbness or weakness in the face, arm, or leg, especially if it only affects one side
  • confusion or difficulty speaking or understanding someone else’s speech
  • difficulty seeing, which may affect one or both eyes
  • difficulty walking, feeling dizzy, losing balance or coordination
  • severe headache for no apparent reason

Individuals should call 911 immediately if a person shows any of these symptoms.

Some recommendations to help manage blood pressure include the following.

Medical management

Managing blood pressure with medication can be complex.

Research shows sufficient blood pressure management is important in preventing and treating stroke, as high blood pressure is a major risk factor in 25–50% of strokes. The research authors note that blood pressure-lowering therapies can reduce the risk of stroke or recurrent strokes.

However, some scientists disagree on what level to bring the blood pressure down to, as lowering it too much could negatively affect health. The American Guidelines for Management of Hypertension recommend reaching a target of 130/80 mm Hg in everyone. That said, doctors should exercise caution with this target guidance, as a rapid dip in blood pressure can be harmful.

However, a 2022 study suggests lowering levels to less than 140/90 mm Hg in people with severe disease of the major blood vessels in the brain may increase their risk of another ischemic stroke. The study author argues that a more individualized approach to managing blood pressure is necessary.

Steps to take

The CDC details actions someone can take to reduce their risk of stroke, including:

  • managing co-occurring medical conditions they may have, for example, diabetes
  • quitting smoking, if applicable
  • eating a nutritious diet of fiber-rich vegetables and fruits and restricting the amount of certain food types, for example, trans fats
  • maintaining a moderate weight, which can lower a person’s risk for stroke and other medical conditions
  • getting 2 hours and 30 minutes of moderate-intensity physical activity per week, if possible
  • limiting the consumption of alcohol

A person should also consult their doctor regularly to review their medications, particularly if they are for health issues with links to stroke, including:

  • cholesterol medication
  • blood pressure medication
  • diabetes medication
  • heart disease medication

It is also important for a person to take their medications as their doctor prescribes them.

A high blood pressure reading above 130/80 mm Hg can increase the risk of stroke.

Elevated blood pressure can cause various physiological changes, such as damage to the blood vessels of the brain and bleeding in the brain. These changes can cause ischemic or hemorrhagic strokes or strokes due to small vessel disease.

Knowing the signs of stroke — including sudden one-sided weakness and difficulty speaking, seeing, or walking — can save lives. A person who experiences these symptoms needs immediate medical attention.

Individuals can also manage their blood pressure and reduce their risk of stroke by eating a nutritious diet, getting regular exercise, and avoiding smoking, if applicable.