Melanoma is a skin tumor caused by the overproliferation of abnormal melanocytes, and it is an early sign of skin cancer. Melanoma mostly occurs in middle-aged and elderly people, and it is difficult to attract attention at the early stage of development, but once detected, it is easy to develop lymph node metastasis and endanger patients’ lives. Therefore, it is crucial to understand the early symptoms of melanoma. How to determine the early stage of melanoma? First, it is an asymmetrical rash. One side of the rash is more stable, while the other side expands to the periphery and shows irregularity and epidermal roughness. Secondly, the rash is darkened or hypopigmented. There may be light brown – thick brown – black, dark red – red – purplish red, gray-blue – cyan – gray-blue, or even loss of pigment. Third, the rash is not clear around the border. Or one side is clear while the other side is blurred, giving a vague feeling. 4. The rash grows rapidly in a short period of time and multiplies within 1 to 2 months. If the rash of congenital pigmented nevus is larger than 6 mm in diameter, especially if it occurs on the palm of the hand or the sole of the foot, and if the diameter of the pigmented nevus is more than 15 mm, it already suggests the possibility of malignancy. Fifth, whether the rash is elevated. The surface of the rash is not elevated at first, and then it is slightly elevated and gradually forms nodules. Or the surface has vesicles, crusts, pus, running water, especially bloody water.