The scalp is usually divided into five layers, from outside to inside: skin, subcutaneous tissue, capillary tendon membrane, subtenoid layer and periosteal layer. Hematomas formed by rupture of scalp blood vessels after head trauma are usually divided into subscalp hematomas, subcapsular tendon hematomas and subperiosteal hematomas depending on the location. Subcutaneous hematomas are usually small in size, and sometimes they are easily mistaken for depressed skull fractures because the tissue around the hematoma is swollen and elevated, but the center is depressed, and they need to be differentiated by skull x-ray. Subcapsular hematoma can spread to the whole head due to the laxity of the tissue in this layer, which can lead to shock or anemia in children and frail patients. Subperiosteal hematomas are characteristically confined to a particular cranial area, bounded by a bone suture, and are seen after cranial damage, such as birth injuries. Smaller scalp hematomas may resolve themselves in about 1 to 2 weeks; huge hematomas may take 4-6 weeks to resolve. Local puncture and aspiration under strict sterilization can be followed by appropriate pressure bandaging. To avoid infection, puncture aspiration is generally not used for small ones. When dealing with scalp hematoma, focus on the possibility of skull injury or even brain injury. Pay attention to the occurrence of anemia in infants and children.