Stroke, emergency care - How do doctors diagnose a stroke?
BMJ Group Medical Reference
If your doctor thinks you may have had a stroke, he or she will give you a thorough physical check.
If you have had a severe stroke, you may black out (lose consciousness). But if you are awake, the doctor will check how alert you are by asking you simple questions. He or she will probably ask you your name and what the date is. You might also be asked if you know where you are.
Your doctor will then shine a light in your eyes to make sure your pupils respond properly. He or she will also ask you to look left and right, then up and down. You may also be asked to smile or shrug, and the doctor may test whether you can hear quiet noises or feel a gentle touch on your skin.
The doctor will then check your muscles by asking you to squeeze someone's finger, push with your hands or legs, or kick your legs out. Very often people who have had a stroke will be weak on one side of their body, so it's important to test the strength of your legs and arms.
Your doctor will also check your reflexes by tapping your knee or another joint with a small hammer. Someone who has had a stroke may have reflexes that are much faster and stronger than usual.
If you can get out of bed, your doctor may want to see if you can walk properly. He or she will also make sure that your speech is normal, because some strokes make it hard for people to talk. Other tests include asking you to write something simple on a piece of paper, or to remember the names of a few simple objects (like a hat, a car, and a dog) and then say them back to the doctor after a few minutes.
Doctors use brain scans to find out what type of stroke you've had, where it is, and what treatment you should have. It's usually best to have a brain scan as soon as possible after doctors think you may have had a stroke. You should definitely have a brain scan within 24 hours. But you may have one much more quickly. Scans can show where the stroke has happened and if the stroke has caused any other problems.
You may have:
A CT (computerised tomography) scan: You lie down on a bed that moves slowly through the scanner. The scanner takes lots of x-rays of your brain to see if there is anything unusual there. It provides very detailed pictures and may be the only test you need
An MRI (magnetic resonance imaging) scan: This looks very like a CT scanner. You lie on a bed which moves you through the tunnel of the scanner. The scanner uses a strong magnetic field to get detailed pictures of your brain. You may have an MRI scan if the results from the CT scan aren't clear.