Over 100,000 people in the UK suffer a stroke each year, with there currently being around 1.2 million survivors living in the country.
Many people note that despite how common strokes are they remain unaware of what the actual causes of a stroke are.
Depending on which of the two types develops, causes and outcomes can differ.
What both have in common is they restrict blood flow to the brain. This leads to a reduction in the brain’s oxygen levels, which can cause tissue damage.
Here, NR Times breaks down why a stroke may occur and what risk factors there are behind each different type.
What are the different types of stroke?
There are two main types of strokes: ischaemic and hemorrhagic.
Ischemic strokes make up nearly 90 percent of all cases and they materialise when an artery which provides blood and oxygen to the brain becomes blocked.
A hemorrhagic stroke is much less common, but happens when an artery leading to the brain bursts and starts to leak blood around or in the brain.
Causes of an ischaemic stroke
The brain is only able to function properly when its arteries supply it with oxygen-rich blood, meaning any blockages can cause lasting damage.
With a lack of blood flow, the brain is unable to make enough energy to work. If this consists for more than a few minutes, brain cells will begin to die.
This is exactly what happens in an ischaemic stroke, but there are a range of reasons as to why these blockages develop.
One of the main causes is when the arteries around the head narrow, which makes it harder for the blood to pass through.
This can also lead to something called atherosclerosis, which is where substances in the blood (such as fat or cholesterol) stick to the sides of the arteries.
Blood can build up on these deposits, causing a further increase in pressure and a reduction to the brain’s oxygen supply.
There are a number of reasons for these blockages, with the most common ones being around a person’s lifestyle.
For example, smoking can increase the risk of a stroke by up to 50 percent.
This is because nicotine not only narrows the arteries, but it also makes the heart beat faster, causing an increase in blood pressure.
Excessive alcohol intake, obesity and high cholesterol levels are also all listed as major risk factors when it comes to ischaemic strokes.
Problems with the arteries around the heart can also lead to an ischaemic stroke.
Irregular heartbeats, heart attacks and other irregularities around this area can again limit the blood’s oxygen levels.
Causes of a hemorrhagic stroke
Hemorrhagic strokes are most common in people ages 45 to 70, but they affect a lot more younger people than an ischaemic stroke.
These are caused after the arteries around the brain burst and cause bleeding.
Depending on where the artery is can affect the outcome of the hemorrhagic stroke.
If the bleeding occurs within the brain, blood shooting out at high pressure can kill some cells.
Bleeding on the surface increases the pressure in the protective layer between the brain and the skull, potentially causing more cell loss.
This bleeding is normally caused by chronically high blood pressure. In many cases, the increased pressure can cause the arteries to expand and weaken, meaning a split in them is more likely to take place.
A rarer cause of hemorrhagic stroke is where the blood vessels around the brain are connected abnormally, causing further stress on the brain. These are congenital (present at birth) but the reason for their occurrence is currently unknown.
Again, the best way to reduce the risk of an hemorrhagic stroke is to make healthy lifestyle choices.
