Stroke is an episode, in which the blood supply to the brain is disrupted, due to a block or damage to a blood vessel causing bleeding in and around the brain. Stroke can be simply thought as a brain attack, which can cause varying damage to the body, depending on the type of stroke. It is important to know the types of stroke and identify the warning signs to prevent further damage.
Blood circulation is essential for every part of the body. The brain particularly reacts to any changes in the blood supplied to it. If there is any damage to the blood vessels reaching the brain, the blood supply and hence the oxygen reaching the brain gets affected. Similarly, when there is a block in an artery carrying blood to the brain, insufficient blood supply to the brain can cause deficiency of oxygen in the brain cells.
However, all strokes are different and the effect caused by it varies from person to person. Most types of stroke need immediate medical attention and some types may result in long lasting health effects.
Types of Stroke
Stroke is mainly of 3 type and can be classified as
- Ischemic Stroke (clots)
- Hemorrhagic Stroke (bleeds)
- Transient Ischemic Attack (TIA)
Stroke is a medical emergency, due to lack of oxygen to the brain, which can occur at any age, but the risk increases with aging. Knowing the types of stroke can help to understand the potential harm it can cause and emergency medical care can be provided.
Ischemic Stroke (clots)
Ischemic stroke mainly occurs due to the formation of a clot causing blockage in a blood vessel that supplies blood to the neck or brain. Deposition of fat, cholesterol and other substances (plaque) on the inner lining of arteries causes hardening of arteries. It is known as atherosclerosis, in which, due to the plaque deposition on the inner side, there is little space left for the blood to flow through the arteries.
- There is insufficient blood passing through the hardened and narrowed arteries, hence when a clot or thrombus develops at the narrowed artery, the blood flow to the brain is cut off. This is called cerebral thrombosis.
- Sometimes, a blood clot from another location in the body (larger arteries or the heart), can get loosened from its location, enter the circulating blood and reach the brain. It travels through the blood vessels till the clot gets lodged in small blood vessels, thus obstructing the blood flow. This is called cerebral embolism.
Silent stroke (Silent Cerebral Infarction) is an entity, in which a blood clot interrupts blood flow to the brain and is considered as a risk factor for future episodes of stroke.
Ischemic type of stroke is believed to account for around 87% of all stroke cases.
Hemorrhagic Stroke (bleeds)
Hemorrhagic stroke is yet another type of stroke that occurs due to the rupture of a blood vessel of the brain. The resultant bleeding exerts pressure on the brain cells and cause damage to them. Bleeding can occur inside the brain (intracerebral) or in between the brain and surrounding tissue (subarachnoid hemorrhage).
Hemorrhagic stroke results from rupture of a weak blood vessel, which then bleeds in or around the brain. This can result from bulging or ballooning of a weak area in the blood vessel (aneurysm) or even high blood pressure (hypertension). It can stretch and rupture causing bleeding in the brain. Sometimes, congenital malformations of blood vessels like arteriovenous malformation too can cause rupture of blood vessels leading to a hemorrhagic stroke.
Hemorrhagic stroke is seen is around 13% of all types of stroke cases.
Transient Ischemic Attack (TIA)
Transient ischemic attack is the third type of stroke and is a minor form and is different from other types of strokes, as in this, the blood supply to the brain is only temporarily stopped. The episode occurs due to formation of a small clot, but the blood supply is disrupted for a very short period, ranging for about one to five minutes.
An episode of TIA is temporary and usually does not leave any permanent damage to the brain. However, it is considered as a warning sign of future episodes of stroke. It is also called as mini-stroke; hence should be taken seriously and immediate evaluation and treatment should begin. Many people having TIA usually experience stroke in future if not treated in time. Transient ischemic attacks should also be treated with appropriate medical care.
It is important to recognize stroke and treat all types of stroke at the earliest. TIAs appear similar to a major stroke in the beginning, so it is not possible to differentiate between the two.
Warning Signs of Stroke
You can spot a stroke from its warning signs. Watch out for FAST.
- Face – Drooping, numbness or changes on one side of the face
- Arms – Weakness in hands or legs
- Speech – Difficulty in speaking
- Time – Rapidly occurring changes, call emergency
So, any changes that appear like stroke should be thought as a medical emergency and immediate medical aid must begin. Earlier the treatment in stroke, better are the chances of recovery and minimal brain damage.