Stroke: Warning Signs and Risk Factors

A stroke occurs when the blood supply to part of the brain is suddenly interrupted or when a blood vessel in the brain bursts, spilling blood into the spaces surrounding brain cells. Brain cells die when they no longer receive oxygen and nutrients from the blood or there is sudden bleeding into or around the brain. The symptoms of a stroke include sudden numbness or weakness, especially on one side of the body; sudden confusion or trouble speaking or understanding speech; sudden trouble seeing in one or both eyes; sudden trouble with walking, dizziness, or loss of balance or coordination; or sudden severe headache with no known cause. There are two forms of stroke: ischemic - blockage of a blood vessel supplying the brain, and hemorrhagic - bleeding into or around the brain.

What is the Prognosis?

Although stroke is a disease of the brain, it can affect the entire body. A common disability that results from stroke is complete paralysis on one side of the body, called hemiplegia. A related disability that is not as debilitating as paralysis is one-sided weakness or hemiparesis. Stroke may cause problems with thinking, awareness, attention, learning, judgment, and memory. Stroke survivors often have problems understanding or forming speech. A stroke can lead to emotional problems. Stroke patients may have difficulty controlling their emotions or may express inappropriate emotions. Many stroke patients experience depression. Stroke survivors may also have numbness or strange sensations. The pain is often worse in the hands and feet and is made worse by movement and temperature changes, especially cold temperatures.

Recurrent stroke is frequent; about 25 percent of people who recover from their first stroke will have another stroke within 5 years.

Symptoms of a Stroke

If you see or have one or more of these symptoms, don't wait, call 911 right away.

• Sudden numbness or weakness of face, arm, or leg, especially on one side of the body.
• Sudden confusion or trouble speaking or understanding speech.
• Sudden trouble seeing in one or both eyes.
• Sudden trouble walking, dizziness, or loss of balance or coordination.
• Sudden severe headache with no known cause.

Treatment can be more effective if given quickly. Every minute counts.

Risk Factors for a Stroke

Stroke prevention is still the best medicine. The most important treatable conditions linked to stroke are:

• High blood pressure. Treat it. Eat a balanced diet, maintain a healthy weight, and exercise to reduce blood pressure. Drugs are also available.
• Cigarette smoking. Quit. Medical help is available to help quit.
• Heart disease. Manage it. Your doctor can treat your heart disease and may prescribe medication to help prevent the formation of clots. If you are over 50, NINDS scientists believe you and your doctor should make a decision about aspirin therapy.
• Diabetes. Control it. Treatment can delay complications that increase the risk of stroke.
  Transient ischemic attacks (TIAs). Seek help. TIAs are small strokes that last only for a few minutes or hours. They should never be ignored and can be treated with drugs or surgery.

What Research is Being Done?

The National Institute of Neurological Disorders and Stroke (NINDS) conducts stroke research and clinical trials at its laboratories and clinics at the National Institutes of Health (NIH), and through grants to major medical institutions across the country. Currently, NINDS researchers are studying the mechanisms of stroke risk factors and the process of brain damage that results from stroke. Basic research has also focused on the genetics of stroke and stroke risk factors. Scientists are working to develop new and better ways to help the brain repair itself to restore important functions.  New advances in imaging and rehabilitation have shown that the brain can compensate for function lost as a result of stroke.

The National Institute of Neurological Disorders and Stroke (NINDS) conducts and supports research on brain and nervous system disorders. NINDS is one of the more than two dozen research institutes and centers that comprise the National Institutes of Health (NIH).