Ischemic & Hemorrhagic Stroke
What is an Ischemic Stroke?
An ischemic stroke happens when an artery (major blood vessel) that supplies the brain becomes blocked. This interrupts blood flow to part of the brain. The brain cells and tissues begin to die within minutes from lack of oxygen and nutrients. The area of tissue death is called an infarct. About 87 percent of strokes are ischemic strokes.
What is a Hemorrhagic Stroke?
A hemorrhagic stroke happens when a blood vessel that supplies the brain ruptures (bursts open) and bleeds. When an artery bleeds into the brain, brain cells and tissues do not receive oxygen and nutrients. In addition, pressure builds up in the tissues around the artery, causing irritation and swelling in the brain. About 13 percent of strokes are hemorrhagic strokes.
What is a Transient Ischemic Attack?
A transient ischemic attack (TIA) is a temporary interruption in blood flow in the brain. It is similar to a stroke and is sometimes called a "mini-stroke."
A TIA can cause many of the same symptoms as a stroke, but TIA symptoms are temporary. They last for a few minutes or up to 24 hours. If you think someone is having a TIA, call 911 or your doctor's office immediately. It may be a warning sign that a stroke is about to occur. However, you can have a stroke without having a TIA first.
Be prepared for an emergency
- Keep a list of emergency rescue service numbers next to your phone and in your pocket, wallet or purse.
- Find out which hospitals near you are primary stroke centers (have 24-hour emergency stroke care). OHSU is a certified primary stroke center with this type of care.
- Know ahead of time which hospital or medical facility is nearest to your home or office.
Take action in an emergency
- Not all the warning signs occur in every stroke. Don't ignore stroke symptoms, even if they go away!
- Check the time. When did you have the first warning sign or symptom? You'll be asked this important question later.
- If you have one or more stroke symptoms lasting more than a few minutes, don't delay! Immediately call 911 or the emergency medical service (EMS) number so an ambulance (preferably with advanced life support) can take you to the hospital.
- If you're with someone who may be having a stroke, immediately call 911 or the EMS. Expect the person to protest — denial is common. Don't take no for an answer. Get emergency medical help right away.