What Is Stroke-Level Blood Pressure?

A stroke is a very serious and life-threatening medical condition that happens when the blood supply to part of the brain is cut off. So when you hear things like ‘Experts say that 80% of strokes can be prevented’1 it makes you wonder if there are some tell-tale signs that occur before a stroke hits. One of these signs is having elevated blood pressure.

What is considered stroke-level blood pressure? Stroke-level blood pressure is a reading above 180/120 mmHg. When you consider that the ideal blood pressure is between 90/60mmHg and 120/80 mmHg and that you suffer from high blood pressure when it is consistently above 130/90 mmHg you can see how a reading above 180/120 mmHg is dangerously high and needs immediate medical attention.^1,2

Uncontrolled high blood pressure can lead not only to a stroke but also to a heart attack, heart failure or even kidney failure. Some forms of vascular dementia also have prolonged uncontrolled high blood pressure at the beginning. ^1-3

Understanding Stroke

Hypertension, better known as high blood pressure, is the most typical risk factor for stroke. Controlling and reducing high blood pressure is the most effective way to prevent a stroke.4 A common misconception is that strokes only happen to older people, but they happen to young people too. About 10-15% of all strokes happen in people under the age of 50, caused by the same risk factors.¹

What are the common causes of stroke? 

High blood pressure makes your heart work extra hard and puts a strain on your blood vessels. It will cause damage to your arteries and organs over time.² When high blood pressure damages the blood vessels, they will form scar tissue to repair themselves. This scar tissue can “catch” debris like cholesterol particles, leading to these deposits (plaques) that hinder blood flow. This process is called atherosclerosis. 

About 85% of strokes are caused by narrowed vessels in the brain. These narrow or clogged blood vessels restrict the blood flow to the brain and brain cells and can cut off entirely when a blood clot forms. When this happens, it is called an ischaemic stroke.^1-4

These blood clots will typically form in areas where the vessels have been narrowed or blocked over time by these fatty deposit plaques. 

Narrowing of arteries may happen naturally with age or because of damage to the inner lining; however, some things can speed up this process at an alarming rate, like:

• Smoking
• High blood pressure (hypertension)
• Obesity
• High cholesterol
• Diabetes
• Excessive alcohol intake

The remaining 15% of strokes occur when a blood vessel ruptures in or near the brain. This is called a haemorrhagic stroke (or cerebral haemorrhage of intracranial haemorrhage). Chronic high blood pressure or ageing blood vessels are the main culprits here. Because of the enduring strain put on the (ageing) blood vessels, there will come a point where they will no longer hold up under pressure and rupture. A haemorrhagic stroke can also be caused by the rupture of a brain aneurysm.^1-4

Additionally, a mini-stroke, or transient ischaemic attack (TIA), is an event where the blood supply to the brain is temporarily interrupted. It can last a few minutes or carry on for up to 24 hours.

Even though it is called a mini-stroke, there is nothing mini about it and TIAs should still be treated urgently as they can be a warning sign that you are at risk of having a full-blown stroke in the near future, even if your symptoms get better.^3,4

Signs and symptoms of stroke

There is a mnemonic to remember the main symptoms of a stroke and it is the word ‘FAST’:

• Face - look if the face has dropped on 1 side. The person may not be able to smile, displaying a crooked smile or their mount or eye may have dropped down.
• Arms - the person suspected of having a stroke may not be able to lift both arms and keep them elevated, because there is weakness or numbness in 1 arm.
• Speech - listen for slurred or garbled speech, or the person might not be able to speak at all despite appearing to be alert and awake. They may also have trouble understanding you.
• Time - Call an ambulance (999, 112 or 911 depending on where you are) immediately if you see any of these signs or symptoms. The sooner a person receives treatment for a stroke; the less (lasting) damage is likely to happen.³

How does blood pressure increase the risk of stroke? 

When high blood pressure causes damage to the inner lining of blood vessels, they will become narrower.^2,3 Because of the continued strain and pressure put on your (perhaps already damaged or aged) blood vessels by your harder-working heart, they might burst under pressure. A study has shown that the risk of stroke increases continuously above blood pressure readings of approximately 115/75 mmHg. They also state that blood pressure levels are high in most adult populations and that almost two-thirds of stroke burden globally are caused by uncontrolled high blood pressure.⁵

What is the stroke level of blood pressure?

The stroke level of blood pressure is 180/120 mmHg or higher, also called a hypertensive crisis. Call an ambulance straight away if your readings are high and you have trouble breathing, chest pains or any of the signs of a stroke (FAST).^1-4

Ways to check your blood pressure

When you want to have your blood pressure checked, you can visit your GP. A nurse can do it for you and sometimes they even have self-service machines at their clinic.

Typically, they will use a blood pressure monitor, called a sphygmomanometer. This is the first way and the most accurate one if done by a professional. I think we have all seen one of these monitors; it consists of a measuring unit and a cuff that goes on your upper arm. If the cuff is manually inflated, you will also see the doctor or nurse use a stethoscope. The second way is people buy an automatic blood pressure monitor so they can monitor their blood pressure at home without the need to visit the doctor or pharmacy for testing. The third way is a wrist monitor that works similarly, but instead of putting the cuff on your upper arm, you place the cuff on your wrist.⁶

Treating and prevention of stroke

“Am I at high risk for high blood pressure?” you may wonder. Well, let’s see as there are known risk factors that increase the chance of developing high blood pressure. 

This list includes:

• Being overweight
• Having high cholesterol
• Being physically inactive (“sitting is the new smoking”)
• Smoking cigarettes (even being exposed to second-hand smoke!) 
• Having a diet high in sodium, low in potassium and lots of alcohol.

Surely, these things you may be able to change. 

However, there are also factors you cannot do much about, like:

• Your family history of high blood pressure (genetics)
• Race/ethnicity (genetics)
• Ageing
• Being a person assigned male at birth (genetics)
• Chronic kidney disease
• Suffering from obstructive sleep apnoea
• Atrial fibrillation
• Diabetes
• Already having had a stroke, TIA or heart attack.

And then there are the socioeconomic status and psychosocial stresses that are also risk factors for high blood pressure. When you do not have access to basic living necessities, medication or health care, it is deemed rather challenging to make healthy lifestyle changes.^4,7

Preventing a stroke will have to start with controlling your high blood pressure. 

Try to reduce your risk of having a stroke by:

• Eating a healthy diet
• Exercising regularly
• Do not smoke (even second-hand!)
• And try to limit your alcohol intake to no more than 14 units a week 

Additionally, if you have a condition that increases your risk of having a stroke, you need to manage this effectively, i.e., be on top of your medication and look after yourself by following a healthy diet and exercise. 

If you already have had a stroke or TIA in the past, it is even more important that you take care in taking these measures as your risk of having another stroke is greatly increased. ^4,7

Strokes are typically treated with medication; however, treatment depends on what type of stroke you have suffered, what part of the brain was affected, and what has likely caused it.

In some cases, you will need a procedure to remove blood clots or even surgery to treat swelling of the brain and to help reduce the risk of further bleeding (if this was the case for your stroke).^4,7

What you can do at home

Follow a low-fat, high-fibre diet, including lots of fresh fruit and vegetables and whole grains. Limit the amount of salt you are eating to no more than 6g a day (roughly 1 teaspoonful), as too much salt, will increase your blood pressure. 

Combining a healthy diet with regular exercise is the best way to go. It will also help you reach or keep a healthy weight. Additionally, it can also lower your cholesterol and keep your blood pressure in a healthy range. Cut down on your alcohol intake and your caffeine intake (found in coffee, [green] tea, cola and chocolate). And stop smoking already (get help quitting)!^4,7

Medications

Strokes are typically treated with medication; medicines are to reduce blood pressure, reduce cholesterol levels, and prevent and dissolve blood clots.³ 

Several types of medicines can help control high blood pressure and typically people need to take a combination of these medicines. 

Usually, if you are under the age of 55, you will be offered an angiotensin-converting enzyme (ACE) inhibitor of an angiotensin-2 receptor blocker. These both are meant to reduce your blood pressure by relaxing your blood vessels.⁸

However, if you are over the age of 55, or you are of African or Caribbean origin, you will be offered a calcium channel blocker. This one will help reduce your blood pressure by widening your blood vessels. 

Other medications include diuretics that will help by ridding your body of excess fluids and salt through your wee and beta blockers which can reduce your blood pressure by making your heart beat more slowly and with less vigour.

You must take your prescribed medication as instructed because if you miss any doses, it might not work as well. You may need to take blood pressure medicines for the rest of your life, but your medicines may be reduced if your blood pressure stays under control for several years.⁸

Lifestyle Changes

As mentioned before: 

• Daily healthy diet
• Exercise regularly
• Cut alcohol intake
• Cut caffeine intake
• Quit smoking

Complications

Because high blood pressure does not necessarily present with any symptoms to let you know something is wrong, it was rightfully coined the ‘silent killer’.⁹ You might not be aware that your blood is pushing too hard against your arteries, but in doing so it can unleash a lot of complications for your body, most of them due to damage to the blood vessels. 

Well-known complications are a heart attack and a stroke. A heart attack is when the blood supply to the heart muscle tissue is blocked. A stroke occurs when the blood supply to or near the brain is blocked, or if a vessel bursts.⁷

High blood pressure can also create weak spots in the arteries and instead of bursting straight away, they stretch and balloon out from the artery wall filled with blood. This is called an aneurysm. Typically, they will grow slowly but get weaker as they grow. If undiagnosed or untreated they can finally burst and depending on their location cause a brain bleed (haemorrhagic stroke) or a bleed in the abdomen (abdominal aortic aneurysm).

Your heart muscle may also become larger and thicker because of high blood pressure making it work extra hard. This will then cause it to make it harder to pump and supply sufficient blood flow to the rest of your body. This complication is called heart failure.

Another complication is kidney damage. This happens when the blood vessels in the kidneys become weakened and narrow due to the damage done by high blood pressure. The kidneys will then struggle to do their jobs properly and may be unable to remove all the waste and fluid from your body. The extra fluid can then raise the blood pressure, even more, leading to a dangerous vicious cycle.⁷ 

The delicate blood vessels in your eyes can also be damaged by high blood pressure, causing them to get clogged or rupture. This complication is called hypertensive retinopathy, which can cause blurred vision, blindness or even bleeding in the eye! Vision loss can also be caused by a fluid build-up within your retina causing distortion or impairment of your vision or damage to the optic nerve.¹⁰ 

Plaque deposits can reduce the blood flow to the arteries in your legs, which can cause pain and numbness after mild activity. This complication is called peripheral artery disease and tends to go undiagnosed as people think this is just part of getting older. However, it will put you at a higher risk of getting a stroke or a heart attack!⁷

Another complication is called metabolic syndrome. This is the medical term used to describe a combination of diabetes, high blood pressure and obesity. It increases your risk of getting coronary heart disease, stroke and other conditions affecting the blood vessels considerably. On their own, each of these 3 diseases can damage your blood vessels, so you can imagine having all 3 together is fairly dangerous.¹¹

Vascular dementia can also be a complication, again due to the narrowing and blockage of the smaller blood vessels inside the brain. The blood flow to the brain cells is restricted, damaging them and eventually killing them.⁷

When should we seek medical attention

Call an ambulance straight away if your blood pressure levels are 180/120 mmHg or higher and you have trouble breathing, chest pains, or any of the signs of a stroke (FAST).^1-4

If you think you might have high blood pressure, please speak to your doctor. They can measure your blood pressure reading accurately and advise on how to manage it, with lifestyle changes and medication.³

Summary

Over time uncontrolled high blood pressure can lead to a plethora of health problems; however, the good news is that you can take steps to monitor and lower your blood pressure if needed, today! 

If left untreated, high blood pressure may lead to stroke(s), heart disease and heart attack(s), kidney disease and vascular dementia. Speak to your doctor if you think you may have high blood pressure as it is best to treat and manage it as soon as possible. Improve your diet and possibly start a daily exercise regime to stay ahead of these problems, as experts say that 80% of strokes can be prevented.