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How do you know if someone is having a stroke: Think FAST!

Visit us (http://www.khanacademy.org/science/healthcare-and-medicine) for health and medicine content or (http://www.khanacademy.org/test-prep/mcat) for MCAT related content. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Created by Vishal Punwani.

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Video transcript

- [Voiceover] How do you know if someone is having a stroke? What are some of the common symptoms and signs that you might want to look out for? Well, there's something called the FAST test that might help you to remember the most common symptoms and signs of a stroke. So FAST, what does this mean? Well, for starters, it's a mnemonic. So we'll sort of delve into each of these letters in a minute. But it's also a bit of a reference to the need to diagnose strokes really quickly so that they can in turn be treated quickly, because, remember, the longer that treatment is delayed, the longer the person is losing neurons if they're actually having a stroke. And let me put it to you this way. For every minute that blood flow isn't restored to the brain, the person will lose about 2 million neurons. Wow, that is a lot of neurons. So, FAST, not just a mnemonic. And let's actually just jump right in here. So, again, you want a quick, easy way to tell if someone's having a stroke. So you can start by having a look for these common signs and symptoms. So we'll start with the F. The F means Face. Often a person having a stroke won't be able to control their facial muscles as normal. And they might actually develop drooping of their mouth on one side. So you can look at their face and check for any asymmetry. And actually, a good way to bring this out is to ask the person to smile. So they'll try to smile, hopefully. And it might make it easier to look for any drooping on one side. The A stands for Arm. So, for example, since strokes can cause weakness in your limbs, either on one side or on both sides of your body, it's a nice, easy little test to check if the person can raise both their arms. So if there's some difficulty or inability in raising one or both of their arms, then that might suggest a stroke has occurred. Now, the S, the S stands for Speech. And strokes can actually affect areas in the brain responsible for producing speech and understanding speech as well. So the person may have slurred speech or they may not really be able to understand what you're saying to them. So try to get the person talking to see if there are any speech problems. S for Speech. And T is for Time. So we kind of alluded to this earlier because in situations of suspected strokes, which are actually medical emergencies, time is really critical. So if you see any of these signs above, the ones that we sort of just talked about, the person would need to be taken to a hospital right away. So just to clarify what I just mentioned, actually, the first three bits of the mnemonic in particular, these aren't the only symptoms of stroke. They're just some of the more common ones that let you do a pretty quick check to see if someone might be having a stroke. And two last things before we finish up here. So the first thing, you can get more than one of these symptoms happening at one time. And you often actually develop these in combination. So for example, you might get the facial weakness and difficulty speaking and trouble moving your limbs all at once or you might get two of them or you might get all of them plus other symptoms. These are just some of the more common symptoms. And they can happen in combination or not. And the second thing is, well, we want to know how long these symptoms last, right. And it kinda depends on what's happening with the cerebral blood supply, right, 'cause, remember, a stroke is an interruption in your cerebral blood supply, the blood supply to your brain that is severe enough that it actually causes damage to your brain, right. And the other thing is remember that TIAs and strokes can have the same initial symptoms. So by knowing how long the symptoms have lasted, that'll sort of help to tease out whether it's a TIA or a stroke that's going on. And so to further clarify, if without treatment the symptoms go away within about 24 hours, then that generally means that the blood flow to that blocked off area of brain has been restored within 24 hours, which by definition means that a TIA, a transient ischemic attack, has happened and ergo, that's what caused the transient symptoms. So the symptoms will eventually go away when the blood flow is restored within 24 hours, if it's a TIA. On the other hand, if the blood flow isn't restored within 24 hours, then by definition a stroke has occurred. And then the symptoms would last longer than 24 hours and they may start to resolve after treatment. So there's a quick way to assess if someone might be having a stroke, the FAST assessment. And just as a reminder, if you do notice these symptoms, then the person needs to be taken to a hospital right away.