Birthmarks are abnormal manifestations on the surface of the skin of infants since birth, such as pigmented nevi and Mongolian spots, most of which are harmless. Most birthmarks are harmless to the human body. Most of the birthmarks on babies’ bodies are not harmful to their health, except for being unsightly. Mongolian spots are more common, mostly appearing on the waist and hip area of infants, light blue or blue-gray in color, with smooth surface, generally do not need to be treated, and will slowly disappear as the baby grows. Other birthmarks, such as pigmented nevi or hemangiomas, usually do not disappear on their own. Some of them may also be extremely threatening to the infant’s health and life. Congenital pigmented nevi may develop into skin cancer, while certain types of hemangiomas may grow and compress other tissues, requiring prompt treatment to avoid complications. Since birthmarks grow in the skin tissue, they are difficult to remove by normal means and can only be removed by surgery or laser. For larger and deeper birthmarks, surgical removal is required. Most birthmarks can be removed by laser by destroying the pigment or closing the blood vessels. There are different types of birthmarks, some of which disappear on their own, while others stay with you for the rest of your life. For birthmarks that do not disappear on their own, surgery or lasers are often used to remove them.