Nov 17, - Depending on the location of the injury and its severity, the bruise may cause throbbing, aching, or numbness. Once the initial pain and swelling improve, you should increasingly try to stretch and move the injured finger. Most smashed fingers start to feel much better within three to four days.Immediate relief · Recovery · Bruised fingernail. Aug 30, - Don't keep ice on too long or you can develop frostbite. Elevate it. Letting your hand dangle at your side after smashing your finger will simply increase swelling and that uncomfortable throbbing. Hold it up to reduce the pressure in there.