Most of the nail melanomas are genetically determined and hereditary. The causes of melanoma may be related to race, with white people having a higher incidence of melanoma than people of color. However, some behaviors in life can also have triggered melanoma. Long-term exposure to ultraviolet light is the cause of melanoma, when sunlight hits melanocytes, more melanin is produced, the skin darkens, and tan freckles or moles, the vast majority of which are benign, can form. However, too much UV radiation can destroy the structure of melanocytes and cause them to grow out of control into tumors. In addition, it is important to avoid frictional stimulation of moles, as about 30-50% of malignant melanomas are associated with external stimulation.