Hypertension And Stroke


When you think of someone who’s had a stroke, do you imagine a frail old lady, or an overweight middle-aged businessman? Think younger. Although stroke is the third leading cause of death (after heart attack and cancer) in people aged over 60 it is also the fifth leading cause of death in people aged 15 to 59 years. According to the American Academy of Neurology, women in their late 40s and early 50s are twice as likely to have a stroke as men in this age group.




Types of stroke

A stroke is the brain’s equivalent of a heart attack, and is the result of a sudden interruption of its blood supply. This causes brain cells to stop working, leading to a loss of control of one or more body parts or functions. There are two main types of stroke:

  • An ischaemic stroke is the most common type (85%) and occurs when a clot causes a blockage in a brain artery; the clot may form in a brain artery or travel there from elsewhere in the circulation to lodge in the brain (embolus)
  • A haemorrhagic stroke (15% of cases) occurs when a blood vessel within the brain ruptures to cause bleeding within the brain or over its surface.

The symptoms and signs of a stroke vary depending on the part of the brain affected, and usually come on quickly. Typically, a stroke may produce:

  • Weakness or loss of movement of part of the body, such as a limb, or several parts, usually on one side (for example, the left arm, left leg and left side of the face).
  • Difficulty speaking.
  • Difficulty swallowing.
  • Confusion, loss of memory or problems with thinking, reading and writing.
  • Numbness or pins and needles in a part of the body.
  • Visual problems.
  • Loss of bladder and bowel control.
  • Collapse or sudden loss of consciousness.

The good news is that the number of strokes has fallen by almost a fifth since the 1990s, which is probably due to improved detection, as well as treatment of risk factors such as high blood pressure and diabetes. Even so, a stroke occurs somewhere in the world every two seconds.  World-wide, 3 million women and 2.5 million men die from stroke every year. Some experts have suggested that stroke may eventually become the most common cause of death worldwide as cancer and heart disease treatments improve.




What to do if you suspect a stroke

If you think someone is having a stroke, it’s vital to act fast – the quicker treatment is started, the more likely it is that brain cells survive. It’s estimated that 1.9 million brain cells are lost for every minute that a stroke is left untreated.

If you think someone is having a stroke, call an ambulance. Urgent assessment is needed to check for the type of stroke, the area of damage, and to ensure the right emergency treatment is given.

In the UK, stroke charities encourage people to Think FAST:

Facial weakness – can they smile? does one side droop?

Arm weakness – can they lift both arms? is one weak?

Speech problems – is their speech slurred or muddled?

Time – if so, it’s time to call 999

If you suspect a stroke – CALL AN AMBULANCE.

Anyone with a suspected acute stroke should be given a brain scan within an hour of arrival at hospital, according to national guidelines.

A mini-stroke or TIA

A so-called mini-stroke is diagnosed when stroke-like symptoms fully resolve within 24 hours. This is known as a transient ischaemic attack (TIA) and is thought to result from small clumps of blood platelets lodging within the brain to temporarily block the circulation to some brain cells. The platelet clots break up and clear before brain cells die from lack of oxygen.

As the symptoms of a mini-stroke resolve, they are often dismissed as exhaustion, migraine, or simply a ‘funny turn’, meaning that many thousands of sufferers don’t recognise that something serious is wrong. But a TIA is an important warning sign that a full blown stroke may occur in the future – often during the next 24 hours.

The symptoms of a TIA are initially identical to those a stroke, so follow the FAST advice above.

If a TIA is treated (for example by taking a drug that lowers platelet stickiness) a full stroke can often be prevented.

High blood pressure and stroke

The main cause of a stroke is having an uncontrolled high blood pressure. Someone in their early forties is 30 times more likely to have a stroke if they have uncontrolled hypertension than someone with normal blood pressure. For every ten people that die of stroke, four could have been saved if their blood pressure was controlled according to high blood pressure treatment guidelines.




Other causes of stroke

The other main cause of a stroke is hardening and furring up of the arteries, which is linked with high blood pressure, and is also more likely in people with poorly controlled diabetes, abnormal cholesterol balance, or with raised blood levels of an amino acid, homocysteine, which damages artery linings.

Other factors which increase the risk of a stroke include smoking (which raises blood pressure, damages arteries and thickens the blood so it is more likely to clot), drinking excessive amounts of alcohol (which makes blood pressure rise) and lack of exercise. Just 30 minutes of brisk activity every day can significantly reduce your risk of stroke by lower blood pressure and cholesterol levels.

Other factors that can trigger the formation of small blood clots and cause a stroke include an irregular heartbeat (atrial fibrillation), damaged heart valves, and producing too many blood cells (polycythaemia).

Some risk factors for stroke are unavoidable, such as the genes you have inherited, and increasing age, but you can reduce your risk by making diet and lifestyle changes and ensuring your blood pressure is well controlled.

Your risk of experiencing a fatal stroke is increased by:

  • 420% if you have had a previous stroke or TIA
  • 140% if you have atrial fibrillation (fast, irregular heart beat)
  • 84% if you have high blood pressure
  • 83% if you have impaired glucose tolerance or poorly controlled diabetes
  • 38% if you have coronary heart disease.

However, a third of strokes are not predictable from the usual risk factors, and may result from a congenital weakness or abnormality in the brain circulation such as a small ‘berry’ aneurysm.

Women and stroke

Because of hormonal changes associated with pregnancy, and the starting and stopping of hormone treatments such as the oral contraceptives or hormone replacement therapy, women aged 20 to 59 are more vulnerable to strokes than men.

Women are also at increased risk of a stroke due to our rocketing rates of obesity and increasing waist size which is linked with increased blood pressure, raised cholesterol levels, poor glucose handling and heart disease.

Women are also increasingly mimicking male lifestyles and tending to drink more alcohol, lead high-pressured lives with raised stress levels and less time to exercise – all of which put your blood pressure up.

Almost three times as many women die from stroke as from breast cancer and, if you live to the age of 85 years, you have a one in five chance of being affected.




Stroke treatment

Fast treatment is crucial – it can be the difference between someone surviving a stroke and recovering fully. Modern treatments include clot-busting drugs (eg tPA, or tissue plasminogen activator) can reduce death and long-term disability when given within three hours of an ischaemic stroke. In some cases, a procedure in which a clot is mechanically removed from an artery (thrombectomy) is needed.

It’s possible to make a full recovery from a stroke, and to return to an active life, even if a stroke has affected the use of one side of your body.

Following a stroke, different people require different amounts of rehabilitation and support to get back to a life that is as normal as possible.

Physiotherapy, speech therapy, and occupational therapy will help to restore some lost movement, speech disturbance and mobility.

Around a third of people who survive a stroke make a significant recovery within one month.

However, the brain can learn to rewire itself so that other parts of the brain take over some of the tasks of cells damaged by stroke. This means improvements can continue for months, or even years, afterwards.




Preventing a stroke

You can reduce your risk of a stroke by following a healthy diet and lifestyle. Follow the DASH diet for hypertension, which has a low glycemic index with more wholegrains and less processed carbohydrates.

Increasing your intake of fruit and vegetables to 5 or 6 portions daily can reduce the risk of stroke by providing protective  antioxidants, vitamins, potassium, calcium, magnesium, fibre and other substances that lower blood pressure and cholesterol levels. For every 200g of fruit and vegetables you eat, the risk of a stroke decreases by 32%. Citrus fruits, apples, pears and leafy vegetables appear to be the most protective.

Even if you don’t manage to eat five servings of fruit and veg a day, increasing your usual intake by just one serving per day can lower your risk of a stroke by at least 6%. Everyone should aim to eat an extra apple a day to keep the doctor away! In fact, researchers have found that eating an apple a day can reduce the risk of heart disease or stroke by one third, compared with those eating less.

Drinking orange juice, grapefruit juice and pomegranate juice have also been shown to reduce the risk – but if taking any prescribed medications, check for interactions with grapefruit juice first.

Eating oily fish just once a week can also reduce the risk by helping to reduce abnormal blood clotting.

Eating more protein may reduce the risk of stroke – at least in the Japanese population. The risks of a stroke significantly decreased by 40% in those with the highest intake of vegetable protein (soybean products, vegetables and algae) compared with those with the lowest intakes. In contrast, those with the highest intake of animal protein (fish, meat, eggs, milk and dairy products) had a 53%  lower risk of a brain hemorrhage.

Other important factors include:

  • Stopping smoking
  • Maintaining a healthy weight
  • Exercising regularly
  • Cutting back on salt intake
  • Maintaining good intakes of folic acid (and vitamins B6 and B12) which help to lower raised homocysteine levels

If you have high blood pressure, monitor it at home and visit your doctor if it is not at your goal level despite taking your medicines regularly, every day, as prescribed. Your doctor will also check your glucose and cholesterol levels and, if these are raised, ensure you are properly treated to bring these stroke risk factors back down into the normal range.

If your blood pressure is raised, self-monitoring is the key to maintaining good control.

Click here for advice on choosing a blood pressure monitor to use at home.

See my recommended upper arm blood pressure monitors.

Image credit: dhilung_kirat/flickr; johnhain/pixabay; GDJ/pixabay; julenka/pixabay;

 

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