Stroke is a disease that affects the arteries leading to and within the brain. It is the No. 4 cause of death and a leading cause of disability in the United States.

A stroke occurs when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a clot or bursts. When that happens, part of the brain cannot get the blood (and oxygen) it needs, so it starts to die.

Stroke can be caused either by a clot obstructing the flow of blood to the brain (called an ischemic stroke) or by a blood vessel rupturing and preventing blood flow to the brain (called a hemorrhagic stroke). A TIA (transient ischemic attack), or “mini stroke”, is caused by a temporary clot.

The brain is an extremely complex organ that controls various body functions.  If a stroke occurs and blood flow can’t reach the region that controls a particular body function, that part of the body won’t work, as it should.