Overview, Causes, & Risk Factors
A stroke is the death of brain tissue that occurs when the brain does not get enough blood and oxygen. Hemorrhagic stroke is a serious condition that occurs when blood seeps into the brain tissue from a damaged blood vessel.
high blood pressure
abnormal bleeding from blood-thinning medications, such as warfarin or heparin
hemophilia A or hemophilia B, which are blood disorders that prevent normal blood clotting
low numbers of platelets, a type of blood cell involved in blood clotting. Low platelet counts are seen in a number of diseases and conditions, including acute infections and a severe allergic reaction known as anaphylactic shock.
rupture of a cerebral aneurysm, or weakened blood vessel wall within the brain
sickle cell disease, an inherited condition that results in abnormal red blood cells
a group of abnormal blood vessels within the brain known as an arteriovenous malformation or AVM
head injuries
eclampsia, a complication of pregnancy that causes high blood pressure in the mother
The person's risk of hemorrhagic stroke is increased if other risk factors for stroke are also present.
The American Heart Association has recently issued guidelines for stroke prevention. The guidelines discuss risk factors for stroke in 3 categories: nonmodifiable, well-documented modifiable, and less well-documented or potentially modifiable.
The nonmodifiable factors are ones that cannot be changed by the individual and include:
increasing age. A person's risk of stroke doubles each year after age 55.
race. Strokes occur approximately twice as often in blacks and Hispanics as they do in whites.
gender. Men have a 50% higher chance of stroke than women do.
family history of stroke or transient ischemic attack (TIA). A TIA is a short, reversible form of stroke that may serve as an early warning sign of stroke.
Well-documented modifiable risk factors are those that can be changed by the individual in conjunction with his or her healthcare provider. These factors are linked to stroke by strong research findings, and there is documented proof that changing the risk factor lowers a person's risk of stroke. These factors include:
high blood pressure
smoking
diabetes
asymptomatic carotid stenosis, or narrowing of one of the arteries in the neck
sickle cell anemia, a blood disorder that forms abnormal red blood cells
high cholesterol levels in the blood, including total cholesterol and LDL or "bad cholesterol." Low levels of HDL or "good cholesterol" are also cause for concern.
atrial fibrillation, an abnormal heart rhythm
Less well-documented or potentially modifiable risk factors for stroke are those that have less proof of either a link to stroke or the impact of modifying the risk factor. These factors include:
obesity
a sedentary lifestyle with inadequate physical activity
alcohol abuse
high blood levels of homocysteine, a blood component sometimes associated with a higher risk of stroke
drug abuse
blood disorders, such as blood that clots easily or deficiencies of various blood components
hormone replacement therapy (HRT). The AHA currently states that the risk of stroke associated with HRT appears low but needs further study.
use of birth control pills, or oral contraceptives
inflammatory processes, such as a chronic infection with chlamydia
Several recent studies have identified factors that seem to increase or decrease the risk of stroke in particular groups of people. These studies, which warrant further investigation, include these findings:
People who were treated for high blood pressure with thiazide diuretics, such as hydrochlorothiazide, had a significantly lower stroke risk than people on ACE inhibitors or calcium channel blockers.
Women ages 15 to 44 who had 2 drinks of wine a day had a 40% to 60% lower risk of stroke than women who did not drink alcohol.
Phenylpropanolamine, a compound contained in appetite suppressants and cold remedies, significantly increased the risk of hemorrhagic stroke in women 18 to 49 years of age. The Food and Drug Administration (FDA) has since asked manufacturers to remove phenylpropanolamine from their product lines.
In one study, people who were treated in emergency departments for transient ischemic attacks (TIA) had a 25% chance of having a stroke or other serious health event within the next 90 days.
What is going on in the body?
A hemorrhagic stroke occurs when blood vessels in the brain burst and release blood into the area around the brain cells. The blood then damages the brain cells. The products released when cells die cause swelling in the brain. Since the skull doesn't allow much room for expansion, this swelling can damage the brain tissue even further.What are the causes and risks of the condition?
A hemorrhagic stroke may be caused by:The person's risk of hemorrhagic stroke is increased if other risk factors for stroke are also present.
The American Heart Association has recently issued guidelines for stroke prevention. The guidelines discuss risk factors for stroke in 3 categories: nonmodifiable, well-documented modifiable, and less well-documented or potentially modifiable.
The nonmodifiable factors are ones that cannot be changed by the individual and include:
Well-documented modifiable risk factors are those that can be changed by the individual in conjunction with his or her healthcare provider. These factors are linked to stroke by strong research findings, and there is documented proof that changing the risk factor lowers a person's risk of stroke. These factors include:
Less well-documented or potentially modifiable risk factors for stroke are those that have less proof of either a link to stroke or the impact of modifying the risk factor. These factors include:
Several recent studies have identified factors that seem to increase or decrease the risk of stroke in particular groups of people. These studies, which warrant further investigation, include these findings:
Symptoms & Signs
What are the signs and symptoms of the condition?
Strokes can cause many different signs and symptoms, depending on the area of the brain that is damaged. Some people have multiple areas of damage. Most strokes begin suddenly, develop rapidly, and cause brain damage within minutes. Signs or symptoms may include:Diagnosis & Tests
How is the condition diagnosed?
Cranial MRIs and cranial CT scans may be ordered to show the type, size, and location of the stroke.Blood tests may be done if the person is on blood-thinning medication. Blood flow tests using ultrasound or angiography may be used.
Prevention & Expectations
What can be done to prevent the condition?
Some hemorrhagic strokes can be prevented through careful control of the underlying disease or disorder. Careful management of sickle cell anemia or hemophilia A or B , for example, can reduce hemorrhage strokes. For individuals with diagnosed cerebral aneurysms, guidelines for monitoring and treatment should be followed.Hemorrhagic stroke from head injuries can be minimized by following sports safety guidelines for children, adolescents, and adults.
The American Heart Association guidelines for stroke prevention address both modifiable and less well-documented or potentially modifiable risk factors.
Measures to reduce the modifiable risk of high blood pressure, a leading cause of stroke, include:
Other measures to reduce an individual's modifiable risk factors for stroke may include:
Measures to reduce less well-documented or potentially modifiable risks for stroke may include:
Some people have early warning signs that they are at risk for strokes. The most common warning sign is what is known as a transient ischemic attack, or TIA. This is a type of reversible stroke that often goes away after a few minutes. These people can often get treatment that will prevent a stroke in the future. For instance, people may be advised to take aspirin or have carotid artery surgery to correct a blockage in a neck artery.
What are the long-term effects of the condition?
Strokes can cause death or permanent disability. Though many people recover some function in the first several months after a stroke, others show no improvement. Some people have several small strokes over time and slowly get worse with each one.What are the risks to others?
Strokes are not contagious and pose no risk to others.Treatment & Monitoring
What are the treatments for the condition?
If someone has the early warning signs of stroke, the emergency medical system should be contacted immediately. These signs include a sudden onset of:Supportive therapy may also be needed with some strokes. This may include an artificial breathing machine, or ventilator, and an artificial feeding tube if the person cannot swallow.
Rehabilitation services can help to improve a person's function after a stroke. Physical therapy and other therapy, such as speech therapy or occupational therapy, may be used to maximize recovery.
What are the side effects of the treatments?
Side effects depend on the treatments used. For example, a ventilator may sometimes cause damage to the lungs or an infection.What happens after treatment for the condition?
After the person is stable, treatment of the risk factors for stroke, as well as the cause of the stroke, is important to prevent further strokes. For instance, stopping smoking and controlling high blood pressure, diabetes, and high cholesterol are advised for most people.Many people need assistance of one form or another after a stroke. This may range from using a walking cane to needing 24-hour-a-day skilled nursing care. Ongoing therapy to improve function is usually advised for at least 6 months if the person is able.
How is the condition monitored?
People having a stroke are often admitted to the hospital for close monitoring. Once the person is stable, he or she can often be sent home or to a skilled nursing facility or rehabilitation center for further therapy. Any new or worsening symptoms should be reported to the healthcare provider.Attribution
Author:Gerald C. McIntosh, MD
Date Written:
Editor:Ballenberg, Sally, BS
Edit Date:01/31/01
Reviewer:Eileen McLaughlin, RN, BSN
Date Reviewed:07/13/01
Date Written:
Editor:Ballenberg, Sally, BS
Edit Date:01/31/01
Reviewer:Eileen McLaughlin, RN, BSN
Date Reviewed:07/13/01
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