I injured my ankle about a week ago, i slipped while going down stairs. constant pain around on outside ankle bone and occasionally radiates up leg ?

Have it x-rayed: If you are getting constant pain that radiates, you should have it x-rayed, it could have a fracture or it could be ligamentous injury. You may need it immobilized for a short time to allow it to calm down then start range of motion exercises as soon as you can tolerate them . You can take an antiinflamatory to help with the discomfort. If there is a fracture you would need it immobilized longer.