In the time that it takes you to read this paragraph, someone in India will have a stroke: Indian Council of Medical Research (ICMR) data show that every 20 seconds, one Indian has a brain stroke. According to a 2017 survey by ICMR, Indians are at higher risk of having a stroke compared with Americans and people from other high-income countries. The survey also showed that there are 105-152 cases of stroke per 100,000 Indians.
Strokes are the second leading cause of death and the third leading cause of disability worldwide, according to the World Health Organization. Every year, 29 October is observed as the World Stroke Day. This year the focus is on prevention. Read on to know the types of brain strokes and some steps you can take to avoid them:
What is a stroke?
A stroke occurs when a blood vessel that carries oxygen to the brain either bursts (or ruptures) or is blocked by a clot. This leads to the death of that part of the brain as well as other brain cells as they can’t get the blood (and oxygen) they need.
Why does a stroke occur?
A stroke occurs due to one of two reasons. One, a blood clot prevents blood from reaching the brain, causing an ischemic stroke. Or two, a blood vessel in the brain ruptures, leading to severe bleeding in the brain which in turn causes a haemorrhagic stroke.
Ischemic strokes make up about 87% of all strokes, and strokes from bleeding constitute the remaining 13%, according to the American Stroke Association.
What are the different types of brain strokes?
An ischemic stroke occurs when a blood clot blocks the flow of blood to the brain.
If the clot is formed in another part of the body, usually the heart or carotid artery, and enters the brain’s blood vessels, thus blocking it – then it is called an embolus.
If the clot is formed inside an artery that supplies blood to the brain, it is called a thrombus.
Medications that dissolve a clot can prevent severe damage if given quickly after stroke symptoms appear.
What causes a haemorrhagic stroke?
Haemorrhagic stroke occurs when a blood vessel in the brain ruptures or leaks due to weakness in the vessel wall. This leads to blood flowing into or around the brain and creates swelling and pressure.
Haemorrhagic strokes are the most deadly, causing about 40% of stroke deaths, according to the National Stroke Association, US.
Two main reasons behind a hemorrhagic stroke are aneurysms and arteriovenous malformations (AVMs). Brain aneurysms occur when a part of the brain’s arterial wall bulges and fills with blood. An AVM, on the other hand, is an abnormal tangle of blood vessels (both arteries and veins) which disrupts normal blood flow and oxygen circulation.
Haemorrhagic strokes can either lead to intracerebral haemorrhage, which means that the bleeding will occur within the brain or subarachnoid haemorrhage, which means the bleeding will occur within the subarachnoid space – the area between the brain and the tissues that cover the brain.
Can you prevent a stroke?
Some of the same factors that improve overall heart and brain health also help to lower the risk of stroke. These include:
If you have high blood pressure, try to reduce it by cutting down on salt, junk food and saturated fats.
Maintaining an ideal body weight prevents the occurrence of several stroke-causing diseases such as high blood pressure and diabetes.
Make exercise a daily habit as it increases blood flow, thus reducing the chances of formation of a blood clot.
Control diabetes as high blood sugar provides a favourable environment for clot formation.
Quit smoking as it makes the blood thick and promotes plaque formation in the walls of arteries.
This article was written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health. For more information, please read our article on Stroke: Causes, Early Signs, Symptoms, Treatment and Prevention.