I sprained my ankle and it's pretty swollen. How do i know if i need an XR?

If you can't walk four steps after a sprain or if there is pain at certain points on the ankle, then it's a good indication to get an X-ray.
 
Transcript: "Hi. That's a great question. You certainly don't want to be running to the urgent care or emergency room if you think that this may be something that's going to get better. So, in general, there are some rules that you can apply that we as physicians use when we're trying to evaluate whether or not an X-ray is needed for a sprained ankle. Now, just know that most sprained ankles are soft tissue injuries and you're not going to see any changes on the X-ray. But here's some general rule of thumb. First of all, if you can't walk after you've sprained your ankle, you can't walk for four steps or more, or even if you decide to wait a few hours, or 12 hours later, or even the next morning and you still can't walk four steps, that would be a good indication for an X-ray. The other things are locations of where your pain is, where you may think to yourself, it's sore there, it hurts there. This may be an indication for an X-ray. I'll show you on my own foot. If on the inside of the ankle you have pain at the tip of the ankle bone here, or along the back part of the ankle bone here, then you may need an X-ray in this region. And then on the outside of your foot, if you have pain at the tip of your ankle bone here, or behind that ankle bone on this side, then that is also an indication for an X-ray. Sometimes someone may have a foot pain. And if your foot hurts in the mid zone here, and you have pain right at the base of what we call the fifth metatarsal on the outside of your foot, right at the base of this phone here, this is the outside of your foot-- or if you happen to have pain in that same foot, right along this bone called the navicular bone, in the in the midfoot, then those are all good reasons to go ahead and seek medical care and get an X-ray of either your ankle or your foot. And of course, if you have any concern at all, seek medical care. And then your health care provider can follow up and determine whether or not you need an X-ray. Thanks for the question."