If you have a hard bump on your leg, there are mainly the following cases to consider: 1. If the hard bump is red and painful to touch, this is considered folliculitis, which can be disinfected with iodophor cotton balls and coated with erythromycin cream. 2. Consider a cyst. If the cyst is a surgical procedure, it cannot be treated with drugs. 3. Consider lipoma. If it is a lipoma, it is also a small surgery to remove it if necessary, and a small surgery can be done on an outpatient basis. 4.Dermatofibroma. It may be related to local friction insect bites, etc. Dermatofibromas can be left untreated or removed with minor surgery. 5. Scars. A dark red scar that protrudes from the skin surface. Mostly caused by trauma, burns, and infection. The treatment of scars cannot be surgically removed, and surgical removal may lead to larger scars. The recommendation is local closed treatment to soften the scars.