What is a stroke?
Stroke, also called brain attack, cerebrovascular accident, or cerebral infarction, is a very serious condition in which the brain is not receiving enough oxygen to function properly. Stroke often results in serious and permanent complications and disability. It is the fifth-leading cause of death in the United States.
The brain requires a steady supply of oxygen in order to function effectively. Oxygen is supplied to the brain from the blood that flows through arteries. A stroke occurs when an artery that supplies blood to the brain becomes blocked or ruptures and begins to leak. When this occurs, the area of the brain that is not getting enough oxygen-rich blood from that affected artery is damaged. Even a brief interruption in blood supply can cause significant problems. Brain cells begin to die after just a few minutes without blood or oxygen. Death of brain tissue is cerebral necrosis.
Due to both the physical and chemical changes that occur in the brain with stroke, damage can continue to occur for several days, even after blood flow is restored. A stroke can also cause a buildup of pressure inside the skull, which can result in permanent injury to the brain.
The extent of the damage done to the brain during a stroke varies depending on such factors as the type of stroke, the area or areas affected, and how much time passes before the stroke is treated.
A stroke is a potentially life-threatening condition. Recovery from stroke and the specific ability affected depends on the size and location of the stroke. A small stroke may result in only minor problems, such as weakness in an arm or leg. Larger strokes may cause paralysis, loss of speech, or even death.
Seek immediate medical care (call 911) if you or someone you are with has one or more symptoms of a stroke, including confusion, disorientation, slurred speech, inability to move a part of the body, or passing out. Treatment within one hour of the stroke is the best chance of a good recovery. The word “FAST” can help you remember the symptoms of a stroke: Facial drooping, Arm weakness, Speech difficulty mean it’s Time to call 911.
What are the different types of stroke?
Stroke is a form of cardiovascular disease. There are two main types of strokes:
Ischemic stroke occurs when a blood vessel that supplies the brain becomes blocked (usually by a blood clot or a small fragment of cholesterol plaque from the carotid artery) and impairs blood flow to part of the brain. The starving brain cells and tissues begin to die within minutes. About 86% of strokes are ischemic.
- Hemorrhagic stroke occurs when an artery in the brain ruptures or leaks blood. Chronic hypertension is often the cause. When an artery bleeds into the brain tissue, brain cells and tissues do not receive adequate oxygen and nutrients. In addition, fluid pressure builds up in surrounding tissues and irritation and swelling occur. About 14% of strokes are hemorrhagic.
What are the signs of stroke?
Symptoms of a stroke can differ depending on the type of stroke, the area or areas affected, how much time passes before the stroke is treated, and individual factors.
In some cases, symptoms of a stroke occur suddenly but they can be mild and vague. These symptoms include:
These symptoms may also be warning symptoms of a condition called a transient ischemic attack (TIA). A TIA is sometimes incorrectly referred to as a small stroke or ministroke. In contrast to a stroke, the effects of a TIA are temporary and generally go away by themselves.
Despite the temporary effects of a TIA, it is important to understand that symptoms of a TIA need immediate medical evaluation and treatment. Symptoms of a TIA generally indicate underlying problems in blood circulation in the brain and can be a warning sign of an upcoming stroke.
Serious symptoms that might indicate a life-threatening condition
Stroke is a potentially life-threatening condition. Seek immediate medical care (call 911) for any of the following warning signs and symptoms of stroke:
Abnormal pupil size or nonreactivity to light
Change in level of consciousness or alertness, such as passing out or unresponsiveness
Difficulty understanding speech
Drooping of the face
Garbled or slurred speech or inability to speak
Impaired breathing or swallowing
Paralysis or difficulty moving the face, a leg or arm, or entire side of the body
- Severe weakness
F.A.S.T. response to stroke symptoms
Treatment of ischemic strokes includes medication to dissolve the blood clot, but the timing is critical. The medicine is most effective and increases the chance of a good outcome when it is administered within a few hours and preferably within one hour of when stroke symptoms start. Act “FAST” when you see the symptoms of a stroke: Facial drooping, Arm weakness, Speech difficulty mean it’s Time to call 911.
What causes a stroke?
A stroke occurs when an artery that supplies blood to the brain becomes blocked or ruptures and begins to leak. The two main types of stroke are ischemic and hemorrhagic.
The primary causes of ischemic stroke include cerebral embolism and cerebral thrombosis:
Cerebral embolism is a clot that forms in a part of the body outside the brain. A cerebral embolism travels through the bloodstream and lodges in an artery that supplies blood to the brain. This blocks blood flow to the brain.
- Cerebral thrombosis occurs due to a buildup of plaque and inflammation in the brain arteries. This is called atherosclerosis. Atherosclerosis narrows the brain arteries and reduces the amount of oxygen-rich blood that reaches the brain tissue, which can lead to symptoms of a transient ischemic attack (TIA), a warning sign of an impending stroke. Arteries narrowed by atherosclerosis are more likely to develop a blood clot (cerebral thrombosis) that completely blocks blood flow to an area of the brain.
Hemorrhagic stroke is caused by cerebral hemorrhage (bleeding). A cerebral hemorrhage occurs when an artery in the brain breaks open or leaks blood into the surrounding brain tissue, causing a buildup of pressure and damage to brain tissue. A ruptured brain aneurysm can cause a cerebral hemorrhage and hemorrhagic stroke.
What are the risk factors for stroke?
The main risk factors for stroke are high blood pressure, high cholesterol, diabetes, obesity, and smoking. It is estimated that 1 in 3 adults in the United States has at least one of these leading risk factors for stroke. Your own risk of stroke depends on heredity, natural processes, and your lifestyle.
In the last 20 years, the rate of stroke declined significantly. The decline was greater in white men than white women, and more in white people than other racial and ethnic groups. However, the differences in the rate of stroke by age, sex and race are less pronounced with increasing age. Reasons for the decline include lower rates of smoking, use of medications to lower blood pressure, and less of an impact from atrial fibrillation and cardiovascular disease, two other risk factors for stroke.
Stroke risk factors include:
African American ancestry, especially among younger adults
Atherosclerosis (buildup of plaque on the walls of the coronary arteries)
Atrial fibrillation (a type of cardiac arrhythmia)
Blood clotting disorders
Brain aneurysm (life-threatening bulging and weakening of a brain artery)
Excessive alcohol consumption
Family history of heart disease or stroke. (Studies show stroke and high blood pressure share some of the same genetic factors.)
High blood pressure (hypertension)
Older age. (For each decade of life after age 55, the chance of having a stroke more than doubles.)
Prior transient ischemic attack (TIA, or mini-stroke)
How do you prevent stroke?
Most strokes (upwards of 80%) are preventable. You cannot change your genetic- and age-related stroke risk factors, but there are many controllable risk factors. You may be able to prevent or lower your risk of stroke by:
Eating a diet low in saturated fat and high in fiber, whole grains, fruits and vegetables
For females, getting screened for high blood pressure before taking birth control pills and throughout pregnancy
Maintaining a healthy weight
Monitoring your blood pressure on a regular basis
Not drinking alcohol or limiting alcohol intake to one drink per day for women and two drinks per day for men
Not smoking. This is especially important for females taking hormonal birth control. Avoid secondhand smoke as well.
Participating in a regular exercise program
What are the diet and nutrition tips for stroke?
A healthy, nutritious diet is important both to prevent a first-time stroke and a second stroke. The strategy is identical to a heart-healthy diet plan to lower the risk of heart disease and heart attack. In general, you want to consume a low-fat, low-salt, and high-fiber diet.
Diet and nutrition tips for stroke include:
Beans, lentils and other legumes
Fats that are monounsaturated, in the form of nuts, seeds, avocados, eggs, fish, and olive oil
Fruit, preferably fresh or frozen rather than dried or canned
Whole-grain breads and pastas. You can also add quinoa, couscous, and other whole grains to many dishes.
- Vegetables in the low-starch category, such as broccoli, kale, endive and many more
Avoid these items:
Artificially sweetened beverages, which were shown to increase a woman’s risk of stroke (consuming more than two drinks a day)
Salty or sugary foods
- Saturated fats
Ask your healthcare provider for dietary guidance. Your doctor can refer you to a dietitian for additional help.
What are some conditions related to stroke?
Conditions related to stroke include:
Carotid artery disease. Atherosclerosis in the arteries supplying blood to the brain can reduce blood flow to the brain and can also generate pieces of plaque that get lodged in a smaller blood vessel branch in the brain.
Coronary artery disease. Commonly known as heart disease, CAD is narrowing of the arteries that supply blood to the heart muscle. Fatty plaque buildup and atherosclerosis is the main cause. A heart attack from CAD is equivalent to a stroke caused by a cerebral thrombosis. The risk factors for stroke and CAD are the same: high cholesterol, high blood pressure, diabetes, obesity, and smoking, among others.
- Transient ischemic attack (TIA). Also known as a “mini-stroke,” a TIA is the result of a temporary reduction in blood flow to a part of the brain due to atherosclerosis or a blood clot. Having a TIA is a risk factor for stroke.
How do doctors diagnose stroke?
Diagnosis of stroke is oftentimes based on the characteristic signs and symptoms affecting one side of the body: facial drooping, arm weakness, and speech problems (garbled speech or not being able to speak). Computed tomography (CT) or magnetic resonance imaging (MRI) of the brain and its blood vessels is necessary to confirm the diagnosis, determine if the stroke is ischemic (caused by a blood clot or embolus) or hemorrhagic (caused by bleeding), and locate the block or bleed.
The doctor will check blood sugar (glucose) levels because low blood sugar (hypoglycemia) can cause symptoms that appear like a stroke.
Other tests may include:
Angiography of the coronary and carotid arteries to identify a possible source of the blockage
Blood coagulation tests to check for an underlying blood clotting or bleeding disorder
Heart tests, such as an electrocardiogram to check heart function
- Swallow test to evaluate the ability to swallow, although this is not performed until the patient is stable
If known, it is important to mark the time when the affected person was last observed normal (before symptoms started). This information helps emergency responders determine the most beneficial treatment.
How is a stroke treated?
Stroke is an emergency. Call 911 if you think you or someone you are with is having a stroke. The greatest chance for recovery occurs when treatment starts as soon as possible. Emergency treatment may include medications that dissolve blood clots, reduce or control brain swelling, or help protect the brain from damage and ischemia (lack of oxygen).
If diagnosed early, some strokes can be successfully treated before the development of permanent neurological damage and complications, such as paralysis and disability. Emergency and long-term stroke treatments depend on the type of stroke, your risk factors, lifestyle, medical history, and other diseases and conditions you have.
General treatments for stroke
Treatment for stroke includes:
Intensive monitoring and stabilization of heart rhythm and vital signs. In some cases, this may require CPR and advanced life support measures, such as intubation and mechanical ventilation to support breathing.
Monitoring of heart rate and rhythm with an electrocardiogram (known as an EKG or ECG)
Monitoring of neurological status
Monitoring of pressure inside the brain
Supplemental oxygen to increase the amount of oxygen that is delivered to the brain tissue and the rest of the body
- Treatment of abnormal heart rhythms (cardiac arrhythmias) with medications and possibly cardioversion or electrical defibrillation
Medications to treat ischemic stroke
Certain medications are only for an ischemic stroke caused by a blood clot in a brain artery. Doctors do not use these medications to treat a stroke caused by bleeding in the brain (hemorrhagic stroke) because they can increase bleeding and worsen a hemorrhagic stroke.
Medications for an ischemic stroke may include:
Aspirin, which helps prevent new blood clots (antiplatelet)
Heparin, which helps prevent new blood clots (anticoagulant)
- Thrombolytic (clot-dissolving) drugs, which break up and dissolve the clot that is causing the stroke. Thrombolytic drugs are most effective if given within a few hours of the onset of stroke symptoms.
Surgical treatments for stroke
In some cases, surgery may be performed to treat or prevent a stroke. Surgical procedures may include:
Carotid endarterectomy to prevent a stroke or a recurrent stroke. This surgery removes the built-up plaque in the arteries running through the neck up to the brain and improves blood flow to the brain.
Cerebral endarterectomy performed by a neuroradiologist, when indicated, to retrieve the offending cholesterol plaque
Surgery to prevent or treat certain types of hemorrhagic stroke caused by a brain aneurysm (weakening or bulging of a brain artery that can rupture or leak blood into the brain)
- Surgery to reduce dangerously high levels of pressure on the brain tissue caused by a ruptured or leaking brain aneurysm
Other treatments for stroke
Other treatments for stroke often come after the emergency measures for stroke to help people regain their strength, avoid complications, and prevent a subsequent stroke. Other treatments include:
Palliative care to improve overall quality of life for families and patients
Regular follow-up care to help monitor your treatment and progress and to address any problems or complications promptly
- Rehabilitation, including occupational, speech and physical therapy to help strengthen the body, increase alertness, reduce fatigue, and improve overall long-term health and functional ability. Rehabilitation begins before you leave the hospital.
Complementary treatments for stroke
Some complementary treatments may help people cope in the aftermath of a stroke. These treatments, sometimes referred to as alternative therapies, are used in conjunction with traditional medical treatments. Complementary treatments are not meant to substitute for traditional medical care. Be sure to notify your doctor if you are consuming nutritional supplements or homeopathic (nonprescription) remedies as they may interact with the prescribed medical therapy.
Complementary treatments may include:
Nutritional dietary supplements, herbal remedies, tea beverages, and similar products
How does stroke affect quality of life?
The impact of stroke on health-related quality of life is subjective, based on how the person perceives his or her own physical and mental health (or how loved ones around the person do). Quality measures include perceptions of mobility, pain, self-care, depression, activities of daily living, and social relationships, among others. Based on many population-based studies, stroke reduces health-related quality of life in the categories of independent living, social relationships, and mental health.
Women report lower health-related quality of life than men one year and five years after stroke, although the difference is greater at one year than five years. Additional risk factors for lower quality of life in women compared to men include age at time of stroke, level of independence before stroke, stroke severity, and the presence of a mood disorder, such as depression or anxiety. Sex differences in quality of life were more pronounced in younger age groups.
Best-practice stroke care (for example, administration of clot-dissolving medicine within three hours of an ischemic stroke) has been shown to improve health-related quality of life and survival.
Stroke care goes well beyond medication management. It involves the stroke team providing the patient and his or her caregiver the skill set and training to succeed with rehabilitation and life at home. The American Stroke Association website has a comprehensive guide to life after stroke. Being aware of coping skills and stroke resources can help prevent frustration and stress during recovery. The more severe and disabling the stroke, the more coping skills you are likely to need.
Coping tips for stroke include:
Be an active participant in your (or your loved one’s) care.
Be open to new routines, including using assistive devices like a cane or walker.
Celebrate small successes.
Connect with a stroke support group.
Engage in talk therapy with a counselor.
Go to all stroke rehabilitation appointments. If this is a problem, ask your doctor or other team member about telerehabilitation. You perform the exercises at home with supervision from a therapist on the computer.
Learn how to perform tasks using the unaffected side of your body, with help from an occupational therapist.
Live a healthy lifestyle by eating right and moving around every day.
Reach out to family and friends for support.
Talk to a social worker at the hospital or recovery center if you need help, including financial assistance.
- Use all the stroke resources available to you, which may include physical, occupational, speech, and recreational therapy.
If you care for someone who has had a stroke, arrange respite care resources to temporarily relieve you in your duties as caregiver. Respite care ranges from family and friends taking over for you, to paid in-home care, to residential facilities. Ask the hospital or rehabilitation center for referrals.
What are the potential complications of stroke?
Complications of a stroke can be life-threatening. Stroke can also lead to permanent disability. Complications of a stroke can be caused by the stroke itself, such as brain damage, or from long-term immobility and disability. You can help minimize your risk of some complications by following the rehabilitation and stroke recovery plan you and your healthcare professional design specifically for you. Complications of stroke include:
Incontinence and urinary tract infection
Muscle wasting and permanent deformities of the arms or legs (contractures) due to decreased mobility of the limbs
Permanent difficulties with walking, talking, understanding speech, and movement of the limbs
What is the survival rate and prognosis for stroke?
Stroke prognosis varies considerably by the type of stroke, where in the brain the stroke occurred, time to treatment and type of treatment, access to rehabilitative services, your overall health and age, and other factors, including race or ethnicity.
Some strokes have a poor prognosis with significant disability. Other strokes cause minimal damage and impairment. In either case, stroke recovery takes place over several months. The brain has an incredible capacity to relearn and compensate for how to accomplish tasks. Many people regain some or all function lost in the beginning.
Many studies report the number of deaths due to stroke per year, but stroke survival rate studies are more informative on an individual level, and are not common. A French study of a cohort of stroke patients determined a relative survival rate from either ischemic stroke or hemorrhagic stroke. The relative survival rate reflects stroke-related deaths.
The relative survival rate for ischemic stroke, for both genders and all ages, was approximately 80%, 77%, 72%, and 62% at 2, 3, 5 and 10 years, respectively. This means, for example, that 80% of people who had a stroke are alive two years later; 77% are alive 3 years later, and so on.
Relative survival for hemorrhagic stroke was lower than for ischemic strokes, with a 42% survival rate at 10 years. Survival rates decreased with increasing age and, in younger age groups, relative survival is lower in females vs. males.
Stroke survivors who suffer a second stroke have a poorer prognosis and lower survival rate than people who have a one-time event.
Time to treatment is the key to minimizing disability from a stroke and improving prognosis. Many people do not know all the signs of stroke or the need to call 911 when someone is experiencing these symptoms:
In the United States, someone has a stroke every 40 seconds and someone dies of stroke every 4 minutes. It is the fifth-leading cause of deaths in the U.S., but 80% of strokes are preventable. To prevent stroke and disability, know your risk factors and the signs and symptoms of stroke.
The National Institute of Neurological Disorders and Stroke and American Stroke Association recognize May as National Stroke Month.