What Is a Stroke?

Request an Appointment

Please call the Coordinator at 617-732-6600 or submit a request through our secure online form.

A stroke—or brain attack—occurs when blood flow to the brain gets disrupted. Disruption in blood flow is caused when either a blood clot blocks one of the vital blood vessels in the brain (ischemic stroke), or when a blood vessel in the brain bursts, spilling blood into surrounding tissues (hemorrhagic stroke).

The brain needs a constant supply of oxygen and nutrients to properly function. Even a brief interruption in blood supply can cause serious problems, as brain cells begin to die after just a few minutes without blood or oxygen. A loss of brain function occurs with brain cell death. When this happens, symptoms of a stroke may include impaired ability with movement, speech, thinking and memory, bowel and bladder, eating, emotional control and other vital body functions. Recovery from stroke and the specific ability affected depends on the size and location of the stroke. A small stroke may result in problems such as weakness in an arm or leg, whereas larger strokes may cause paralysis (inability to move part of the body), loss of speech or even death.

What Causes a Stroke?

A stroke occurs when a blood clot limits the flow of blood and oxygen to the brain or when a blood vessel bursts or leaks. A blood clot can have many causes, including poor diet, smoking or excessive alcohol use. A blood vessel can burst due to conditions like diabetes or high blood pressure, which can damage or weaken the arteries and make them more susceptible to rupturing.

What Are the Different Types of Strokes?

The two most common types of stroke are ischemic and hemorrhagic. Each type of stroke has a different cause:

  • Ischemic stroke: When blood clots or fatty plaque deposits greatly narrow or completely block a blood vessel, it reduces blood flow to the brain
  • Hemorrhagic stroke: When an artery in the brain leaks or ruptures, the pressure from the leaked blood causes damage to brain cells
  • Transient ischemic attack (TIA): Known as a mini stroke, a TIA is like an ischemic stroke, but the blockage is temporary, often less than five minutes. While a TIA may not lead to lasting complications, any blockage may require treatment to prevent a full stroke

What Are the Risk Factors for Stroke?

A number of factors can contribute to your risk of having a stroke. Risk factors that can be controlled through lifestyle changes or medical treatment include:

  • Diabetes can damage blood vessels over time because of high blood sugar
  • Excessive alcohol use. The more alcohol you consume, the greater your risk
  • Heart disease can increase your risk of plaque buildup and clots
  • Heart rhythm disorders can cause blood clots that can lead to stroke
  • High blood pressure can damage or weaken blood vessels
  • High red blood cell count thickens the blood and can cause clots
  • High cholesterol causes plaque buildup and hardening of the arteries
  • Obesity contributes to an increased risk of stroke
  • A sedentary lifestyle and lack of exercise can increase risk
  • Smoking doubles your risk for stroke

Other risk factors for stroke that can't be controlled include:

  • Age: As people get older, their risk of stroke increases
  • Gender: Men are more likely to have a stroke
  • Previous stroke: Once you have a stroke, you are at much higher risk of having another one
  • Genetics: A family history of strokes increases your risk

What Are the Signs and Symptoms of a Stroke?

Signs of a stroke may be sudden—although they could be either mild stroke symptoms or aggressive—and include:

  • Weakness or numbness of the face, arms or legs, especially on one side of the body
  • Confusion or difficulty speaking or understanding
  • Problems with vision, such as dimness or loss of vision in one or both eyes
  • Dizziness or problems with balance or coordination
  • Problems with movement or walking
  • Loss of consciousness or seizure
  • Severe headaches with no other known cause, especially if sudden onset

All of the above warning signs may not occur with each stroke, so do not ignore any of these symptoms. Even if the symptoms go away, take action immediately.

Other, less common, symptoms of stroke may include the following:

  • Sudden nausea or vomiting not caused by a viral illness
  • Brief loss or change of consciousness, such as fainting, confusion, seizures or coma

Are the Symptoms the Same for Ischemic and Hemorrhagic Strokes?

The signs for ischemic stroke symptoms and hemorrhagic stroke symptoms can be similar but there can also be slight differences. Those experiencing an ischemic stroke may have numbness or weakness on one side of the body or face and difficulty with balance, vision and speaking. Often a key hemorrhagic stroke symptom is a sudden and severe headache, which doesn't always occur in other types of strokes.

Are the Symptoms of Stroke in Women the Same as in Men?

The risk of stroke increases with age. Because women generally live longer than men, more women experience strokes. While the main symptoms of a stroke in women are the same as in men, women more commonly report these symptoms of a stroke:

  • Difficulty breathing
  • Feeling weak or fainting
  • Hiccups
  • Seizures
  • Hallucinations
  • Sudden behavioral changes
  • Vomiting or nausea

What to do When you See Signs of Stroke

Time matters for a patient suffering a stroke. Get immediate medical attention at the first sign or symptom of a stroke, even if the symptoms appear to fade. The FAST acronym can help you tell if someone may be experiencing a stroke:

  • Face: Does the face droop when you ask the patient to smile?
  • Arms: Is the patient able to raise both arms equally well?
  • Speech: Is the patient's speech slurred or strange when asked to repeat a basic phrase?
  • Time: Getting medical attention quickly is imperative, so call 911 immediately

How is a Stroke Diagnosed?

A healthcare provider will conduct a physical exam as part of diagnosing a potential stroke. From there, doctors can use imaging tests to measure blood flow in the brain. Those tests include:

  • CT scan: An X-ray image to show bleeding in the brain or damaged brain cells
  • MRI: The magnetic fields of magnetic resonance imaging create images that show minor changes in brain tissue
  • CTA: A computed tomographic angiography is an X-ray of blood vessels
  • MRA: A magnetic resonance angiography uses MRI technology to better understand arterial blood flow
  • Doppler sonography: Also known as a carotid ultrasound, the sound waves can provide an image of if plaque has built up inside arteries

What Is the Treatment for a Stroke?

There are several options for treating a stroke. The best stroke treatment will depend on the patient’s age, health and medical history as well as the severity, location, cause and type of stroke. In some cases, surgery may be necessary. Several types of stroke surgery may be performed to help treat a stroke, or to help prevent a stroke from occurring. Those surgeries include:

  • Simple and complex intracranial bypass procedures
  • Craniectomy and hemispheric decompression for stroke patients with a large area of brain affected
  • Carotid endarterectomy, skull base approaches to aneurysm clipping, and AVM resection to prevent stroke or stroke recurrence while minimizing disturbance of normal brain tissue
  • Stereotactic radiosurgery to treat AVMs inaccessible by other means
  • Endovascular surgery to treat intracranial aneurysms, AVMs, and extracranial and intracranial obstructions (angioplasty, stenting)

Surgical stroke treatment options may differ based on the type of stroke. Ischemic stroke treatment clears the blockage, which can be done via endovascular surgeries. In a hemorrhagic stroke, surgeons may need to relieve the pressure on the brain and repair the blood vessel.

Stroke treatment may also include medications, both in an emergency setting and following initial stroke treatment. Drugs that can break up blood clots, such as a recombinant tissue plasminogen activator (TSA), are a common ischemic stroke treatment. In the case of a hemorrhagic stroke, patients may be prescribed medicines to thin the blood or lower blood pressure.

For patients who suffer a stroke, specialists at our Center for Cerebrovascular Diseases deliver rapid, accurate and advanced assessment and treatment. A stroke is an emergency, and the greatest chance for recovery from stroke occurs when treatment is started immediately.

Innovative Stroke Treatment Video

Read the video transcript Innovative and Minimally Invasive Treatments for Stroke and Brain Aneurysm Patients.

Brain Blood Clot Removal Procedure

This video animation demonstrates a mechanical thrombectomy for revascularization to remove a blood clot in the brain. Quick medical treatment to remove the clot is critical to prevent ischemic stroke. Learn more about the Center for Cerebrovascular Diseases.

Recovering from a Stroke

Stroke recovery starts with recuperation from any emergency procedures followed by stroke rehabilitation. After a stroke, the patient is closely monitored until the emergency portion of the stroke has passed. A healthcare team will assess the impact of the stroke, which may have damaged brain tissue and require rehabilitation. Stroke recovery usually goes through seven stages as patients gradually recover motor skills and normal brain function. A patient's stroke rehabilitation program is

based on their individual needs and abilities and can include range of motion exercises, sensory reeducation, mirror therapy and complex movement exercises.

Stroke FAQs

What Can You Do to Prevent a Stroke?

A patient's best opportunity to prevent a stroke comes in controlling risk factors for stroke. Key changes to the way a patient lives can help, at least in part, prevent a stroke. They include:

  • Eating healthy can limit the fatty plaque buildup in blood vessels that can lead to a blockage
  • Stopping smoking and limiting alcohol use helps keep blood vessels and arteries healthier
  • Physical activity and maintaining a healthy weight will improve overall health and reduce the risk of a stroke
What Are the Five Warning Signs of a Stroke?

The sudden or severe onset of any stroke warning signs should prompt immediate emergency medical attention. They include:

  • Sudden numbness or weakness on the side of the body in the face, arm or leg
  • Sudden confusion or difficulty speaking
  • Sudden vision changes or difficulty seeing out of either eye
  • Sudden loss of balance or difficulty with coordination or walking
  • Severe headache with no known reason
How Long Does a Stroke Last?

The timetable for how long a stroke can last varies greatly. Some stroke episodes—or brain attacks—last minutes, others hours and some can last days. The sooner a patient gets medical attention, the better the chance of survival and recovery.

Can a Stroke Cause Permanent Brain Damage?

The damage a stroke can have on a brain can be life-threatening. Brain damage, sometimes serious, is considered permanent following a stroke.

Can You Have Multiple Strokes?

Patients who have suffered one stroke are susceptible to another. In an average year, nearly 25% of people who suffered one stroke experience a second. Medical treatment and lifestyle changes can reduce the risk of multiple strokes.

Learn more about Brigham and Women's Hospital

For over a century, a leader in patient care, medical education and research, with expertise in virtually every specialty of medicine and surgery.

About BWH