Finger black common causes are the following aspects: 1, due to the finger for a long time suffered to the adverse physical and chemical factors stimulation, thus leading to local skin thickening, pigmentation, manifested as black symptoms, common such as long time cold, long time wind, sun, friction, long time humidity, etc., are due to adverse factors stimulation; 2, and then there is a factor is due to poor blood circulation. The local tissue hypoxia, ischemia will lead to tissue necrosis, accordingly there will be a black situation, but generally there will be white in the early stage, and then hypoxia, ischemia continues to aggravate will lead to black, that is, the finger necrosis; 3, there is another aspect of the factor, the finger suffered trauma, the local will produce the corresponding hemorrhage, there will be corresponding subcutaneous petechiae, which will be manifested in the finger blackened, darkened symptoms. It is recommended that patients go to the hospital in a timely manner, according to the diagnosis to take the appropriate treatment.