What causes the glans to turn black after circumcision?

After circumcision, black discoloration of the glans may result from ruptured capillaries and other causes. During surgery, rupture of local capillaries can lead to significant bleeding, which accumulates under the skin or within tissues and later manifests as bruising or dark discoloration. Pressure dressing is commonly applied after circumcision to prevent postoperative bleeding; however, if the dressing is too tight, it may cause bluish-black discoloration (cyanosis) of the glans. Substantial bleeding during surgery can accumulate beneath the skin or in surrounding tissues, and as it is absorbed, localized bruising and darkening may occur.