<s>[INST] i hit my left thumb in the door while closing it. Initially the pain was unbearable the nail turned blue and black from base to half nail. its the 3rd day still have pain, radiating to left arm, throbbing and swollen at the base, with a slight yellow color. please advise [/INST] Hello, it may be entirely a soft tissue injury or displaced fracture may also be suspected depending on the severity of trauma. Yellow discoloration may be due to trauma related glycolysis, where the nail separates from the nail bed. Since throbbing pain is felt still on the 3rd day it's better to have a physical examination, an x-ray if required, along with ibuprofen...which relieves the pain and edema too. Hope it helps. </s>