Skin cancer is a malignant proliferative lesion of the skin and its related tissues, which is caused by various reasons and should be carefully prevented in daily life. There is no scientific unification on the cause of skin cancer, but after research, it is found that some behaviors and factors may be the causative factors of skin cancer. If healthy skin is exposed to UV radiation for a long time, the chance of skin cancer will be greatly increased. If the skin is directly exposed to strong sunlight for more than two hours a day, the skin may be severely damaged, thus inducing skin cancer. Meanwhile, frequent exposure to irritants, such as harmful chemicals like tar or asphalt that can induce cancer, may also lead to skin cancer. Ionizing radiation and radiation can also cause certain damage to the skin, and if the skin is exposed to such substances for a long time, it will also lay the hidden danger of skin cancer. In addition, some untreated skin diseases, such as inflammation or ulcers, may also lead to cancer in the affected area if they persist for a long time. After skin cancer is developed, some abnormal skin growth symptoms will appear accordingly, and easy bleeding is also one of the symptoms. Early detection can be treated by surgery or radiotherapy, and the treatment effect is better before the cancer cells metastasize to lymph nodes. The cause of skin cancer is still unclear, but there are many causative factors, such as long-term exposure to ultraviolet and ionizing radiation and radiation, long-term exposure to toxic substances or skin ulcers that remain untreated for a long time may also cause cancerous changes.