Stroke Overview
Stroke is the leading cause of adult disability in the United States. Through advances in medical care, more people than ever before survive a stroke.
A stroke most often occurs when blood flow to the brain becomes blocked (called ischemic stroke). One of the following problems may cause this blockage:
- a build-up of fatty substances (atherosclerotic plaque) along an artery's inner lining causes it to narrow, reduces its elasticity, and decreases its blood flow
- a clot forms in an artery supplying the brain
- a clot forms somewhere in the body (often the heart) and breaks free, traveling to and becoming lodged in an artery supplying the brain
A stroke may also occur if a blood vessel breaks and bleeds into or around the brain. If this happens, it is called a hemorrhagic stroke.
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
Modifiable risk factors:
- high blood pressure
- narrowing of arteries supplying the brain due to atherosclerosis
- high cholesterol levels, particularly LDL (low-density lipoprotein) cholesterol
- smoking
- obesity
- lack of exercise
- drinking excessive amounts of alcohol
- diabetes mellitus
- atrial fibrillation (abnormality of heart rhythm) that is treatable
Non-modifiable risk factors:
- a prior stroke or pre-existing cardiovascular disease other than stroke
- a prior transient ischemic attack (a temporary interrupting of the brain's blood supply, often called a mini-stroke)
- age: 60 or older
- family members who have had a stroke
- race: African-American
Some patients experience a "warning stroke" or transient ischemic attack (TIA). These are symptoms of a stroke that resolve completely, usually within hours. Such patients are at a significantly increased risk of having a full-blown stroke sometime in the near future.