A stroke occurs due to a decrease or blockage in the brain’s blood supply. A person experiencing a stroke needs immediate emergency treatment.
Stroke is the fifth leading cause of death in the United States. In fact, nearly 800,000 people (source) have a stroke each year. That equates to around one person every 40 seconds.
There are three main types of stroke:
- Ischemic stroke: This is the most common type of stroke, making up 87% of all cases. A blood clot prevents blood and oxygen from reaching an area of the brain.
- Hemorrhagic stroke: This occurs when a blood vessel ruptures. These are usually the result of aneurysms or arteriovenous malformations (AVMs)Trusted Source.
- Transient ischemic attack (TIA): This occurs when blood flow to a part of the brain is inadequate for a brief period of time. Normal blood flow resumes after a short amount of time, and the symptoms resolve without treatment. Some people call this a ministroke.
Stroke can be fatal. According to the American Heart Association (AHA), the age-adjusted mortality rate for 2017 was 37.6 in every 100,000Trusted Source stroke diagnoses.
Doctors have made a great deal of progress in managing strokes, meaning that this mortality rate is 13.6% lower than it was in 2007.
This article explains why strokes occur and how to treat them. It also explores the different types of stroke, as well as the steps a person can take to prevent them.
What is a stroke?
A stroke occurs when a blockage or bleed of the blood vessels either interrupts or reduces the supply of blood to the brain. When this happens, the brain does not receive enough oxygen or nutrients, and brain cells start to die.
Stroke is a cerebrovascular disease. This means that it affects the blood vessels that feed the brain with oxygen. If the brain does not receive enough oxygen, damage may start to occur.
This is a medical emergency. Although many strokes are treatable, some can lead to disability or death.
Because ischemic and hemorrhagic strokes have different causes and effects on the body, both require different treatments.
Rapid diagnosis is important for reducing brain damage and enabling the doctor to treat the stroke using a suitable method for the type.
The sections below cover the treatment options for ischemic stroke and hemorrhagic stroke, as well as some general rehabilitation tips for both types.
Ischemic stroke occurs due to blocked or narrowed arteries. Treatment tends to focus on restoring an adequate flow of blood to the brain.
The first step in treatment is to take medications that dissolve clots and prevent new ones from developing. A doctor may prescribe blood thinners such as aspirin or a tissue plasminogen activator injection (TPA).
TPA is an excellent clot-dissolving agent. However, the injection must be administered within 4.5 hours of the onset of stroke symptoms.
TPA can be injected directly into a brain artery or a catheter can be used to physically remove the clot in an emergency. The benefits of these procedures are still being researched.
Other operations that surgeons can undertake to lower the risk of strokes or transient ischemic attacks are available. For instance, a carotid endarterectomy entails opening the carotid artery and eliminating plaque that could burst and go to the brain.
Another option is angioplasty. This involves a surgeon inflating a small balloon inside a narrowed artery using a catheter. Afterward, they will insert a mesh tube, or a stent, into the opening. This prevents the artery from narrowing again.
A hemorrhagic stroke is caused by blood spilling into the brain. The goal of treatment is to stop the bleeding and relieve the pressure on the brain.
Taking medicines to lower brain pressure and control overall blood pressure, as well as preventing seizures and any acute blood vessel constriction is often the first step in treatment.
Anticoagulants or antiplatelet medicines, such as warfarin or clopidogrel, can be used to counteract the effects of blood thinners.
Surgeons can fix some of the blood vessel abnormalities that have caused or potentially cause hemorrhagic strokes.
When a hemorrhagic stroke is caused by an aneurysm — a bulging in a blood vessel that could burst — a surgeon can insert small clamps at the base of the artery.
If the hemorrhage occurs due to an AVM, a surgeon can remove it. AVMs are connections between arteries and veins that can be at risk of bleeding.
A stroke is a potentially life-changing event that can have lasting physical and emotional effects.
Successful recovery from a stroke will often involve specific therapies and support systems, including:
- Speech therapy helps with problems producing or understanding speech. Practice, relaxation, and changing communication styles can all make communicating easier.
- Physical therapy: This can help a person relearn movement and coordination. It is important to stay active, even tho this may be difficult at first.
- Occupational therapy: This can help a person improve their ability to carry out daily activities such as bathing, cooking, dressing, eating, reading, and writing.
- Support groups: Joining a support group can help a person cope with common mental health issues that can occur after a stroke, such as depression. Many find it useful to share common experiences and exchange information.
- Support from friends and family: Close friends and relatives should try to offer practical support and comfort after a stroke. Letting friends and family know what they can do to help is very important.
Rehabilitation is an important and ongoing part of stroke treatment. With the right assistance and the support of loved ones, regaining a normal quality of life is usually possible, depending on the severity of the stroke.
The best way to prevent a stroke is to address the underlying causes. People can achieve this by making lifestyle changes such as:
- Eating a healthful diet
- Maintaining a moderate weight
- Exercise regularly
- not smoking tobacco
- Avoiding alcohol, or only drinking moderately
Eating a nutritious diet means including plenty of:
- whole grains
Be sure to limit the amount of red and processed meat in your diet, as well as cholesterol and saturated fats. Also, moderate salt intake supports healthy blood pressure levels.
Other measures a person can take to help reduce the risk of stroke include:
As well as making these lifestyle changes, taking anticoagulant or antiplatelet medications can also reduce the risk of experiencing another stroke.
Undergoing cardiac artery, carotid artery, or brain aneurysm surgery can also lower the risk of additional strokes, as can some other surgical options still under investigation.
Causes and risk factors
Each type of stroke has a different set of potential causes. Generally, however, stroke is more likely to affect a person if they:
- have overweight or obesity
- You are 55 years of age or older.
- I have a personal or family history of stroke.
- Have high blood pressure
- I have diabetes
- I have high cholesterol.
- If you have heart disease, carotid artery disease, or another vascular disease,
- are sedentary.
- I consume alcohol
- use illicit drugs.
Some studies have found that males have a higher risk of death from stroke than females. However, one 2016 review of studies suggests that these differences do not take into account adjustments for race, age, the severity of the stroke, and other risk factors.
The review explains that the risk of stroke mortality often increases due to age and demographics, rather than the biological differences between males and females.
According to a 2016 analysis, According to a trusted source, African American people have a significantly higher risk of experiencing a first-time stroke. They are also around 60% more likely to experience another stroke within 2 years.
The following sections describe the specific causes of each type of stroke.
This type of stroke occurs due to blockages or narrowing in the arteries that provide blood to the brain. This causes ischemia, or a severely reduced blood flow, which damages brain cells.
Blood clots often cause ischemic strokes. Clots can form in the brain arteries and other blood vessels in the body. The bloodstream carries them into narrower arteries in the brain. Fatty plaque deposits within the arteries can also cause clots that result in ischemia.
Leaky or burst arteries in the brain can give rise to hemorrhagic strokes. Leaking blood exerts pressure on brain cells, causing them to break down. It also lowers the amount of blood that can reach brain tissue following a bleed.
Blood veins in the brain or at the surface of the brain might burst, spilling blood into the brain. Blood may also enter the gap between the brain and the skull as a result of this.
Hypertension, physical trauma, blood-thinning drugs, and aneurysm are all factors that might cause a blood artery to leak or break.
The most prevalent type of hemorrhagic stroke is intracerebral bleeding. This happens when an artery ruptures and blood floods the brain tissue.
Another type of hemorrhagic stroke is subarachnoid hemorrhage. This is a rare occurrence. A subarachnoid hemorrhage occurs when bleeding occurs between the brain and the spinal cord.
TIAs only briefly interrupt the flow of blood to the brain. They are similar to ischemic strokes, in that they occur due to clots.
People should treat them as medical emergencies, even if the symptoms are temporary. They serve as warning signs for future strokes and indicate a partially blocked artery or clot source in the heart.
According to the Centers for Disease Control and Prevention (CDC) Trusted Source, over a third of people who experience a TIA have a major stroke within a year if they do not receive any treatment. Within 3 months of experiencing a TIA, around 10–15% of people will have a major stroke within 3 months.
The symptoms of a stroke often appear without warning. Some of the main symptoms include:
- confusion, including difficulty speaking and understanding speech.
- a headache, possibly with altered consciousness or vomiting.
- numbness or an inability to move parts of the face, arm, or leg, particularly on one side of the body.
- Vision problems in one or both eyes
- difficulty walking, including dizziness and a lack of coordination.
Stroke can lead to long-term health problems. Depending on the speed of the diagnosis and treatment, a person can experience temporary or permanent disabilities after a stroke.
Some people may also experience:
- bladder or bowel control problems.
- paralysis or weakness on one or both sides of the body.
- They have difficulty controlling or expressing their emotions.
Symptoms vary and may range in severity.
Learning the acronym “FAST” is a good way to remember the symptoms of a stroke. This can help a person seek prompt treatment. FAST stands for:
- Face drooping: If the person tries to smile, does one side of their face droop?
- Arm weakness: If the person tries to raise both their arms, does one arm drift downward?
- Speech difficulty: If the person tries to repeat a simple phrase, is their speech slurred or unusual?
- Time to act: If any of these symptoms are occurring, contact the emergency services immediately.
The outcome depends on how quickly someone receives treatment. Prompt care also means that they would be less likely to experience permanent brain damage or death.
The stroke begins rapidly. For the best outcome, a person should receive treatment at a hospital within 3 hours of their symptoms first appearing.
There are several different diagnostic tests a doctor can use to determine the type of stroke. These include:
- Physical examination: A doctor will ask about the person’s symptoms and medical history. They will check muscle strength, reflexes, sensation, vision, and coordination. They may also check blood pressure, listen to the carotid arteries in the neck, and examine the blood vessels at the back of the eyes.
- Blood tests: A doctor may perform blood tests to determine if there is a high risk of bleeding or blood clots by measuring levels of particular substances in the blood, including clotting factors, and checking whether or not an infection is present.
- CT scan: A series of X-rays can show hemorrhages, strokes, tumors, and other conditions within the brain.
- MRI scan: These use radio waves and magnets to create an image of the brain, which a doctor can use to detect damaged brain tissue.
- Carotid ultrasound: A doctor may carry out an ultrasound scan to check blood flow in the carotid arteries and to see if there is any narrowing or plaque present.
- Cerebral angiogram: A doctor may inject a dye into the brain’s blood vessels to make them visible under an X-ray or MRI. This provides a detailed view of the blood vessels in the brain and neck.
- Echocardiogram: This creates a detailed image of the heart, which doctors can use to check for any sources of clots that could have traveled to the brain.
It is only possible to confirm the type of stroke by using a brain scan in a hospital environment.