What Is a Stroke?

Medically Reviewed by Zilpah Sheikh, MD on September 10, 2024
6 min read

Knowing the signs of a stroke is the first step in stroke prevention. A stroke, sometimes called a "brain attack," occurs when blood flow to an area in the brain is cut off. The brain cells, deprived of the oxygen and glucose they need to survive, die. If a stroke is not caught early, permanent brain damage or death can result.

Stroke is the fifth leading cause of death in the United States. It's also one of the top causes of disability.

There are two types of stroke.

Ischemic stroke is similar to a heart attack, except it occurs in the blood vessels of the brain. Clots can form in the brain's blood vessels, in blood vessels leading to the brain, or even in blood vessels elsewhere in the body and then travel to the brain. These clots block blood flow to the brain's cells. 

Ischemic stroke can also happen when too much plaque (fatty deposits and cholesterol) clogs the brain's blood vessels. Atrial fibrillation (Afib) is an irregular heart rhythm that causes clots to form in the heart. Those clots can get loose and travel to the brain. Less commonly, ischemic strokes happen because of a clotting disorder that people are either born with or develop. Almost 90% of all strokes are ischemic.

Hemorrhagic (heh-more-raj-ik) strokes occur when a blood vessel in the brain breaks or ruptures. The result is blood seeping into the brain tissue and damage to brain cells. The most common causes of hemorrhagic stroke are high blood pressure and brain aneurysms. An aneurysm is a weakness or thinness in the blood vessel wall. A brain tumor or cancer that starts in another part of the body and spreads to the brain is another cause of hemorrhagic strokes.

The most common symptoms of a stroke are:

  • Weakness or numbness of the face, arm, or leg on one side of the body
  • Loss of vision or dimming (like a curtain falling) in one or both eyes
  • Loss of speech, difficulty talking or understanding what others are saying
  • Sudden, severe headache with no known cause
  • Loss of balance or unstable walking, usually combined with another symptom
  • Sudden partial or total loss of any senses (vision, hearing, taste, touch, smell)
  • Nausea and vomiting
  • Confusion or agitation
  • Seizures
  • Memory loss (amnesia)
  • Passing out or fainting

Mini stroke symptoms

A mini stroke is a temporary blockage of blood flow to the brain. Another name for it is transient ischemic attack, or TIA. A mini stroke causes the same stroke symptoms listed above, but it only lasts for a few minutes. 

Get familiar with the acronym B.E.F.A.S.T. to learn the signs and symptoms of a stroke and get help quickly:

  • B is for balance –  a sudden loss of balance
  • E is for eyes – vision loss in one or both eyes
  • F stands for face – an uneven smile or weakness in the face 
  • A means arm – weakness in one arm
  • S is for speech – words sound slurred
  • T means time – call 911 right away if you or someone else has symptoms like these

A stroke is a medical emergency. Immediate treatment can save your life or increase your chances of a full recovery.

The treatment for a stroke are medicines that break up blood clots and prevent new clots from forming. An emergency medicine called tissue plasminogen activator (tPA) dissolves clots that block blood flow to the brain. You have to get tPA within 3 hours after stroke symptoms start for it to work. 

Anticoagulants and antiplatelet drugs stop blood cells and platelets from sticking together and forming clots. Your doctor can prescribe these medicines to help lower your risk of a stroke.

These procedures open up a blocked artery and improve blood flow to the brain:

Thrombectomy. A thin tube called a catheter goes through an artery in your upper thigh up to your neck or brain. Then a device called a stent retriever traps and removes the clot and restores blood flow.  

Angioplasty and stenting. The surgeon pushes a catheter into the affected artery. Then a tiny balloon or small mesh tube called a stent goes into the artery to hold it open.

Carotid endarterectomy. The carotid arteries are blood vessels in your neck that supply blood to your brain. This procedure removes sticky plaque that's blocking blood flow through a carotid artery.

Up to 80% of all strokes are preventable. You can control many risk factors before they cause problems.

Controllable risk factors for stroke:

  • High blood pressure
  • Atrial fibrillation
  • Uncontrolled diabetes
  • High cholesterol
  • Smoking
  • Excessive alcohol intake
  • Diet high in saturated fat, trans fat, and cholesterol
  • Obesity
  • Carotid or coronary artery disease
  • Oral estrogen therapy, including hormone replacement therapy (HRT) and birth control pills

Uncontrollable risk factors for stroke:

  • Age (older than 65)
  • Gender (men have more strokes, but women have deadlier strokes)
  • Race (African American people have a higher risk)
  • Family history of stroke
  • A history of migraine headaches

COVID-19 infection may increase the risk for stroke in some people. The immune system response to the virus causes inflammation that might help plaques grow and break up into clots. 

Sometimes, people experience warning signs before a stroke. Other people have no symptoms warning them of a stroke, or their symptoms are so mild they aren't noticeable.

Regular checkups are important to catch problems before they become serious. Report any stroke symptoms or risk factors to your doctor. Your doctor can evaluate your risk for stroke and help you control your risk factors.

Lifestyle changes to help lower stroke risk

Many strokes are preventable with healthy habits like these:

  • Doing moderate- to high-intensity aerobic exercise such as walking and bike riding
  • Eating a diet high in vegetables, fruits, whole grains, low-fat dairy, and fish and low in saturated fat, trans fat, sugar, and salt
  • Keeping your weight in a healthy range
  • Not smoking or vaping, and avoiding secondhand smoke
  • Limiting alcohol to no more than two drinks a day for men and one drink a day for women
  • Seeing a doctor for regular exams and blood pressure checks
  • Controlling stroke risk factors like high cholesterol, diabetes, Afib, and high blood pressure with lifestyle changes or medication
  • Sleeping 7 to 9 hours a night
  • Reducing stress with relaxation techniques like deep breathing, meditation, or yoga

A stroke is a blockage in blood flow to the brain. It can cause permanent brain damage or death if you don't treat it quickly. Learn the signs of a stroke, such as sudden weakness, vision loss, and trouble speaking. Doctors treat a stroke with medicines to break up clots and procedures to remove the blockage. You can prevent a stroke by knowing your risk factors and working with your doctor to control them.

What is the difference between a heart attack and a stroke?

Both a heart attack and stroke happen when a piece of plaque blocks blood flow through an artery. In a heart attack, the blockage prevents blood from flowing to part of the heart muscle. A stroke happens when there is a blockage in blood flow to the brain.  

What are the early warning signs of heart disease?

Sometimes heart disease doesn't cause symptoms and it isn't diagnosed until a heart attack, stroke, or heart failure happens. Signs that you might have heart disease include: 

  • Chest pain, tightness, or pressure
  • Shortness of breath
  • Pain in your neck, jaw, upper belly, or back
  • Numbness or weakness in your arms or legs

Can a stroke be cured?

It is possible to recover after a stroke. How long that takes and how much function comes back is different for each person. Some people make a full recovery, but it can take many months.

What does a stroke feel like?

A stroke feels like sudden weakness or numbness in your arms, legs, or face. Some people have a severe headache. Your speech and vision can also be affected.