Every 40 seconds, someone in the US has a stroke, according to the Centers for Disease Control and Prevention (CDC). A stroke occurs when blood supply to the brain is cut off or reduced. After a stroke, the brain is deprived of key nutrients and oxygen which causes brain cells to die. Fast treatment can help to minimize damage to the brain and other complications. If you suspect someone is having a stroke, call 911 immediately. Strokes can affect people of all ages and backgrounds. Read on to learn about stroke and how to safeguard against it.