There is a raised bag at the back of the head, if there is a history of trauma, it may be a hematoma. Generally speaking, small hematomas and small bags usually do not require special treatment and can disappear naturally in about 1-2 weeks; cold compresses can be applied during the acute period, and hot compresses or rubbing with some blood-stasis-activating solutions can be applied after 3 days. If this raised bag is hard bone with pain, consider physiological coarseness or deformity, poor bone fiber structure, bone tumor; soft tissue mass may be sebaceous cyst, lipoma, neurofibroma or metastasis, you can go to the hospital for cranial CT or MRI examination to make a clear diagnosis to determine the diagnosis and treatment plan.