High blood pressure, also known as hypertension, is a major risk factor for stroke. Blood pressure is the force of blood pushing against the walls of arteries as the heart pumps blood. Hypertension occurs when this force against the artery walls is too high. When blood pressure is elevated, it starts to damage the blood vessels, making them stiffer. This can cause plaque buildup in the arteries and make them more likely to be blocked, resulting in a stroke. Knowing your blood pressure levels and keeping hypertension under control are important ways to reduce stroke risk.
Understanding Blood Pressure Readings
Blood pressure is measured in millimeters of mercury (mm Hg) and is recorded as two numbers:
– Systolic pressure: The pressure in the blood vessels when the heart beats.
– Diastolic pressure: The pressure in the blood vessels when the heart rests between beats.
A normal blood pressure level is less than 120/80 mm Hg. Here is a guide to understanding the different blood pressure ranges:
| Blood Pressure Category | Systolic (mm Hg) | Diastolic (mm Hg) |
|---|---|---|
| Normal | Less than 120 | And less than 80 |
| Elevated | 120-129 | And less than 80 |
| Stage 1 Hypertension | 130-139 | Or 80-89 |
| Stage 2 Hypertension | 140 or higher | Or 90 or higher |
| Hypertensive Crisis | Higher than 180 | And/or higher than 120 |
Prehypertension Increases Stroke Risk
Blood pressure readings in the prehypertensive range of 120-139/80-89 mm Hg are considered elevated. This used to be called prehypertension, but now falls under the new category of elevated blood pressure. While not yet high blood pressure, this range does increase stroke risk compared to ideal blood pressure below 120/80 mm Hg. According to a meta-analysis published in Stroke in 2015, prehypertension was associated with a 55% increased risk of stroke compared to normal blood pressure. Keeping blood pressure optimized in the normal range is important to minimize stroke risk.
Hypertension Stage 1 Puts You at Risk
Stage 1 hypertension is a systolic pressure of 130-139 mm Hg or diastolic pressure of 80-89 mm Hg. At this level, your stroke risk is significantly elevated. According to the American Heart Association, stage 1 hypertension carries over a 200% greater risk of stroke compared to normal blood pressure. Hypertension causes damage to the arteries, making them stiff and more narrow. This makes it easier for blood clots and plaque buildup to block arteries and cut off blood flow to the brain. Keeping stage 1 hypertension under control is important to reduce stroke risk.
Hypertension Stage 2 Greatly Increases Stroke Risk
A systolic pressure of 140 mm Hg or higher or a diastolic pressure of 90 mm Hg or higher puts you in stage 2 hypertension. This is considered a much more dangerous elevation in blood pressure that requires treatment with medication. According to the SPRINT trial published in the New England Journal of Medicine in 2015, stage 2 hypertension carries over a 300% greater risk of stroke compared to normal blood pressure. At this level, the arteries have suffered significant damage and narrowing, making blocked arteries, blood clots, and stroke much more likely. It’s important to lower stage 2 hypertension to safer levels.
Hypertensive Crisis Causes Severe Stroke Risk
A hypertensive crisis occurs when systolic pressure is over 180 mm Hg and/or diastolic is over 120 mm Hg. At this severely high blood pressure, the risk of complications like stroke is extremely high. According to the American Heart Association, hypertensive crisis carries over a 500% greater risk of stroke compared to normal blood pressure. At this extreme pressure, arteries are damaged and blood flow is severely impaired. It’s critical to lower blood pressure quickly and safely in a hypertensive crisis to prevent stroke, organ damage, and other life-threatening outcomes. Seek emergency medical care if blood pressure reaches this dangerous level.
Age and Stroke Risk
Age is another important risk factor to consider. High blood pressure poses an even greater stroke threat as you get older. Systolic pressure tends to increase with age while diastolic pressure starts to drop after the 50s. Wide pulse pressure, or a difference of 60 mm Hg or more between systolic and diastolic pressure, is common in older adults and also linked to greater stroke risk. Keeping blood pressure controlled, especially systolic pressure, is key for lowering stroke risk as you age.
Lifestyle Changes to Reduce Blood Pressure
Making healthy lifestyle changes can help prevent or control high blood pressure, which is essential for lowering your stroke risk. Important lifestyle measures include:
– Maintaining a healthy body weight
– Exercising regularly
– Following a heart-healthy diet such as the DASH diet
– Reducing sodium intake
– Limiting alcohol intake
– Quitting smoking and avoiding secondhand smoke
– Managing stress through relaxation techniques
Making these changes can help optimize your blood pressure and keep it well within the healthy range, giving you the best defense against stroke.
Medications to Control Hypertension
If lifestyle measures are not enough to control high blood pressure, medications may be needed. Many types of blood pressure lowering medications are available. Common options include:
– Diuretics: Help flush out excess fluid and sodium to reduce blood volume
– ACE inhibitors: Block effects of hormone angiotensin to relax and open up blood vessels
– ARBs: Also block angiotensin and open up blood vessels
– Beta blockers: Reduce heart rate and force of heart contraction to lower blood pressure
– Calcium channel blockers: Relax blood vessels and control heart rate
– Other vasodilators: Open blood vessels to improve blood flow
Doctors will determine the most appropriate medication or combination of medications based on your health profile and blood pressure readings. It is important to take hypertension medications as prescribed to keep blood pressure controlled.
Is My Blood Pressure Too Low?
While high blood pressure is a major concern, blood pressure can also be too low. This is called hypotension, defined as blood pressure below 90/60 mm Hg. Low blood pressure is uncommon and usually only temporary. It can be caused by dehydration, blood loss, certain medications, heart conditions, endocrine problems, or even standing up too quickly. While not a direct cause of stroke, very low blood pressure can be associated with poor health outcomes when underlying conditions are present. Consult your doctor if you often have readings under 90/60 mm Hg.
Measuring Blood Pressure
To detect hypertension, regular blood pressure screening is essential. All adults should have their blood pressure checked at least once a year by a healthcare provider. It’s also important to do home monitoring. This gives a better picture of your overall blood pressure since readings can vary.
When measuring blood pressure:
– Don’t smoke, exercise, or have caffeine 30 minutes before
– Sit quietly for 5 minutes before checking
– Sit with back straight and supported
– Keep feet flat and legs uncrossed
– Ensure arm is supported at heart level
– Use appropriately sized cuff on bare arm
– Take 2-3 readings 1 minute apart and record averages
Accurate blood pressure monitoring is key for identifying hypertension early and guiding treatment.
Treatment Goals
The ideal blood pressure goal is below 120/80 mm Hg. For those with hypertension, treatment goals depend on your risk factors and health conditions:
| Patient Profile | Treatment Goal |
|---|---|
| Healthy adults under 60 | Below 130/80 mm Hg |
| Adults over 60 | Below 130-139/80 mm Hg |
| Diabetes or CKD present | Below 130/80 mm Hg |
| CAD present | Below 130/80 mm Hg |
Work closely with your doctor to determine your ideal treatment goal and monitor your progress.
Preventing Stroke with Healthy Blood Pressure
Maintaining healthy blood pressure levels is one of the most effective ways to reduce your risk of a devastating stroke. Know your current blood pressure, understand your stroke risk, and take necessary steps to get hypertension under control through lifestyle changes and medication. With regular monitoring and treatment as needed, you can optimize your blood pressure and significantly lower your chance of stroke.
Conclusion
Elevated blood pressure is a major but controllable stroke risk factor. Prehypertension over 120/80 mm Hg increases risk, with stage 1 and 2 hypertension carrying even greater dangers. A hypertensive crisis over 180/120 mm Hg causes severe risk. Controlling hypertension through diet, exercise, not smoking, and medications when needed is crucial. Regular screening, monitoring at home, and working with your doctor to reach blood pressure treatment goals can help prevent stroke. Know your levels, control hypertension, and reduce this serious threat.