A stroke occurs when blood flow to the brain is interrupted. When this happens, brain cells begin to die because they don’t get the oxygen and nutrients they need to function. Even though a stroke occurs in the brain, the whole body can be affected, causing paralysis, problems with thinking and speaking, emotional difficulties, and other disabilities. A stroke is sometimes referred to as a “brain attack.”
A stroke can occur in individuals of any age, gender, or racial background. In the United States, stroke is more common in African Americans. Risk of stroke increases with age and is higher among people with a family history of stroke.
Stroke is the third leading cause of death in the United States and the most common cause of disability among U.S. adults. More than 700,000 Americans have a stroke each year, and there are about 160,000 stroke-related deaths annually.
The onset of a stroke is a medical emergency. If you experience or witness someone experiencing one or more of the following symptoms, call 9-1-1 immediately.
Other warning signs of a stroke can include double vision, drowsiness, and nausea or vomiting.
By responding to the warning signs of a stroke described above and seeking immediate emergency care, doctors will determine whether you’ve had a stroke. To do so, they’ll inquire about your symptoms and your medical history and perform tests including brain imaging and blood tests. Learn more about diagnosis of a stroke below in “Diagnosis.”
The most common cause of a stroke is a blockage of a blood vessel in the brain or neck. This blockage is called an ischemic stroke. A stroke can also be caused by bleeding into the brain; this type of stroke is called a hemorrhagic stroke.
There are several risk factors for stroke that you can control. Your doctor can help you determine your level of risk and help you take measures to reduce risk. If any of the following conditions or behaviors applies to you, take steps to manage or change them.
The faster a stroke is diagnosed the better, as diagnosis enables doctors to begin appropriate treatment as soon as possible.
A priority of diagnosis is to determine whether the stroke is an ischemic or hemorrhagic stroke. This distinction must be made because it will determine which kind of medication is used—the medicine given for an ischemic stroke can be life-threatening if the patient has had a hemorrhagic stroke. Imaging of the brain with a computed tomography (CT) scan can help the doctor identify the type of stroke.
General steps in diagnosing a stroke include questions about the nature of symptoms and when they began, a medical history that includes questions about risk factors for stroke, and a physical exam that includes a short neurological exam. In addition to CT scan, tests that may be used to confirm a stroke diagnosis include blood tests, an MRI, tests for heart problems (such as electrocardiogram, or ECG or EKG), and imaging tests of the brain and arteries in the neck.
Several other conditions can cause conditions similar to a stroke. A doctor may consider the following conditions before making a diagnosis of stroke: