Skin bruising on a girl’s leg may first be caused by trauma. When the patient is traumatized, the capillaries of the leg may rupture and bleed, which may cause bruising. In addition, if the skin bruises often appear, it may be related to the individual’s constitution, it may be that the capillaries of the patient are fragile, so that the skin bruises easily when slightly bumped. In addition, bruising may also be related to blood clotting abnormalities. Patients with diseases such as hemophilia are also prone to bruising due to a lack of clotting factors. It may also occur in patients with thrombocytopenia. Patients with idiopathic thrombocytopenic purpura and impaired anemia can also have a reduced platelet count, which can lead to bleeding disorders or bruising of the skin. In addition, if you take anti-platelet aggregation drugs such as aspirin for a long time, it can also lead to this condition and skin bruising. Further examination at the hospital is also needed to clarify the diagnosis.