A stroke happens when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack."
Causes, incidence, and risk factors
If blood flow is stopped for longer than a few seconds, the brain cannot get blood and oxygen. Brain cells can die, causing permanent damage.
There are two major types of stroke: ischemic stroke and hemorrhagic stroke.
Ischemic stroke occurs when a blood vessel that supplies blood to the brain is blocked by a blood clot. This may happen in two ways:
Ischemic strokes may be caused by clogged arteries. Fat, cholesterol, and other substances collect on the artery walls, forming a sticky substance called plaque.
A hemorrhagic stroke occurs when a blood vessel in part of the brain becomes weak and bursts open, causing blood to leak into the brain. Some people have defects in the blood vessels of the brain that make this more likely.
STROKE RISK FACTORS
High blood pressure is the number one risk factor for strokes. The other major risk factors are:
People who have heart disease or poor blood flow in their legs caused by narrowed arteries are also more likely to have a stroke.
The chance of stroke is higher in people who live an unhealthy lifestyle by:
Birth control pills can increase the chances of having blood clots. The risk is highest in woman who smoke and are older than 35.
For more information, see: Stroke risk factors
The symptoms of stroke depend on what part of the brain is damaged. In some cases, a person may not know that he or she has had a stroke.
Symptoms usually develop suddenly and without warning. Or, symptoms may occur on and off for the first day or two. Symptoms are usually most severe when the stroke first happens, but they may slowly get worse.
A headache may occur, especially if the stroke is caused by bleeding in the brain. The headache:
Other symptoms depend on how severe the stroke is and what part of the brain is affected. Symptoms may include:
Signs and tests
A complete exam should be done. Your doctor will:
Tests can help your doctor find the type, location, and cause of the stroke and rule out other disorders.
Other tests include:
A stroke is a medical emergency. Immediate treatment can save lives and reduce disability. Call 911 or your local emergency number or seek urgent medical care at the first signs of a stroke.
It is very important for people who are having stroke symptoms to get to a hospital as quickly as possible. If the stroke is caused by a blood clot, a clot-busting drug may be given to dissolve the clot.
Most of the time, patients must reach a hospital within 3 hours after symptoms begin. Some people may be able to receive these drugs for up to 4 - 5 hours after symptoms begin.
Treatment depends on how severe the stroke was and what caused it. Most people who have a stroke need to stay in a hospital.
TREATMENT IN THE HOSPITAL
Clot-busting drugs (thrombolytic therapy) may be used if the stroke is caused by a blood clot. This medicine breaks up blood clots and helps bring back blood flow to the damaged area. However, not everyone can get this type of medicine.
Other treatments depend on the cause of the stroke:
Nutrients and fluids may be needed, especially if the person has trouble swallowing. These may be given through a vein (intravenously) or a feeding tube in the stomach (gastrostomy tube). Swallowing trouble may be temporary or permanent.
Physical therapy, occupational therapy, speech therapy, and swallowing therapy will all begin in the hospital.
The goal of treatment after a stroke is to help the patient recover as much function as possible and prevent future strokes.
The recovery time and need for long-term treatment is different for each person. Problems moving, thinking, and talking often improve in the weeks to months after a stroke. A number of people who have had a stroke will keep improving in the months or years after the stroke.
See: Stroke recovery for information about:
The outlook depends on:
You may recover completely, or have some permanent loss of function.
Over half of people who have a stroke are able to function and live at home. Other people are not able to care for themselves.
If treatment with clot-busting drugs is successful, the symptoms of a stroke may go away. However, patients often do not get to the hospital soon enough to receive these drugs, or they cannot take these drugs because of a health condition.
People who have a stroke due to a blood clot (ischemic stroke) have a better chance of surviving than those who have a stroke due to bleeding in the brain (hemorrhagic stroke).
The risk for a second stroke is highest during the weeks or months after the first stroke. Then the risk begins to decrease.
Calling your health care provider
Stroke is a medical emergency that needs to be treated right away. Call your local emergency number (such as 911) if someone has symptoms of a stroke.