Purple finger skin color may be related to trauma, lung disease, heart disease and other reasons. 1. Trauma: external injuries such as finger squeezing can cause subcutaneous capillary rupture, resulting in subcutaneous bruising, finger skin color purple phenomenon. 2. Lung disease: respiratory failure caused by chronic obstructive pulmonary disease (COPD) can lead to a decrease in the oxygenation index, resulting in purple fingers. 3. Cardiac diseases: such as congenital heart disease, due to the mixing of the arteries and veins, resulting in hypoxia, the symptoms of purple finger skin. It is recommended that people with purple finger skin color go to the hospital in a timely manner to clarify the cause of the disease, under the guidance of the doctor for standardized treatment.