Brain cells need a constant supply of oxygen and nutrients. They are delivered by a network of blood vessels that reach every part of the brain. When something cuts off that supply, brain cells downstream begin to die. The injury that follows is called a stroke.

Most strokes strike when a blood clot becomes lodged in one of the brain's arteries, blocking blood flow. In some cases, the clot forms inside the artery, usually because a cholesterol-filled plaque inside the artery breaks open. This is called a thrombotic stroke. In other cases, a blood clot or a solid mass of debris that originates elsewhere travels to the brain, where it blocks a brain artery. This is called an embolic stroke. A third type of stroke, hemorrhagic stroke, occurs when a blood vessel in the brain bursts.

Since different areas of the brain are responsible for different functions, symptoms of stroke vary. They can be changes in sensation, movement, sight, speech, balance, and coordination. Sometimes a stroke is preceded by one or more transient ischemic attacks (TIAs). These are brief episodes of stroke-like symptoms that last for a few minutes — or possibly up to 24 hours — but that go away on their own.

If you think that you, or someone you are with, is having a stroke, call 911 right away. The sooner you call, the sooner treatment can begin — "time is brain," as emergency room doctors say. The type of treatment depends on the type of stroke that has occurred. If the brain's blood supply is restored quickly and completely, a full recovery with little or no disability is possible. The more widespread the damage, and the greater delay of treatment, the more severe and long-lasting the damage.

Recovery after a stroke depends on how well healthy areas of the brain take over duties that had been performed by the damaged brain tissue. To some extent, especially in children and young adults, recovery is possible because of the brain's ability to compensate for damage in one area by working harder in another — by relying on alternate wiring for some functions or by rewiring around the injured site. When such rewiring isn't possible, rehabilitation techniques can help the brain recover function.

Stroke Articles

Ask the doctor: Atrial fibrillation vs. atrial flutter

Atrial flutter and atrial fibrillation are heart-rhythm disorders that trigger palpitations and lightheadedness. While atrial flutter causes a rapid but regular heartbeat, atrial fibrillation is marked by a rapid but chaotic, unpredictable heartbeat.  (Locked) More »

Faster stroke treatment leads to better results

When a person having a stroke arrives at the hospital, the faster he or she is treated, the better. An initiative to shorten the “door-to-needle” time increased the percentage of people treated within an hour from less than 30% to just over 53%.  (Locked) More »

New guidelines update treatment of atrial fibrillation

New guidelines for treating atrial fibrillation (afib) recommend considering the new oral anticoagulant drugs apixaban (Eliquis), dabigatran (Pradaxa), and rivaroxaban (Xarelto). Compared with warfarin, these drugs are just as effective for preventing a stroke (a serious risk with afib) but are less likely to cause dangerous bleeds in the brain. Other updates include less reliance on aspirin for clot prevention and a newer risk score to better predict a person’s risk of complications from afib.  (Locked) More »

Heart attack and stroke: Men vs. women

Cardiovascular disease poses an equal threat to men and women, but the risks, symptoms, and outcomes for heart attack and stroke can differ along gender lines. For both men and women, awareness of sex-specific risk factors and manifestations of cardiovascular disease can help them protect against life-threatening conditions. (Locked) More »

New advice to help women lower their stroke risk

New stroke guidelines for women, released in February 2014, recommend that women over age 75 get screened for atrial fibrillation, and those ages 65 to 79 should consider taking a daily baby aspirin to prevent stroke. (Locked) More »

Borderline hypertension: When do you need treatment?

Hypertension, defined as a blood pressure reading of 140/90 mm Hg or above, is a primary risk factor for stroke and heart attack. But the perils of hypertension do not suddenly appear as blood pressure readings cross that threshold. Many people fall into the murky zone of borderline hypertension, in which blood pressure is higher than ideal but not yet at a point where medications are recommended. Making diet and lifestyle changes proven to lower blood pressure can prevent or delay the need to take high blood pressure medicines in the future.  (Locked) More »

New techniques for treating atrial fibrillation

A malfunction in the heart’s internal electrical system can disrupt the normal beating sequence and send the two upper chambers into a fast, irregular quiver known as atrial fibrillation. Episodes of atrial fibrillation can cause distressing symptoms or go unnoticed. Either way, untreated atrial fibrillation is a major risk factor for stroke. Medications are the first avenue of treatment to control symptoms and reduce risk. However, a host of new devices and technologies offer promise to people who are not helped by drug treatment. (Locked) More »

Walk more to slash your stroke risk

Men who walk the most have the lowest risk of stroke. A study showed that total walking time, rather than walking pace, determines how much stroke risk is reduced. Walking 30 minutes a day is sufficient to reduce risk. Intense walking will not necessarily produce additional benefit.  People already at higher risk of a stroke because of health conditions can also benefit from moderate walking. Using a step-counting device called a pedometer can motivate people to walk more every day. (Locked) More »