Call 911.
Check the person's airway, breathing, and circulation. If necessary, begin rescue breathing and CPR.
If the person's breathing and heart rate are normal but the person is unconscious, treat as if there is a spinal injury. Stabilize the head and neck by placing your hands on both sides of the person's head, keeping the head in line with the spine and preventing movement. Wait for medical help.
Stop any bleeding by firmly pressing a clean cloth on the wound. If the injury is serious, be careful not to move the person's head. If blood soaks through the cloth, DO NOT remove it. Place another cloth over the first one.
If you suspect a skull fracture, DO NOT apply direct pressure to the bleeding site, and DO NOT remove any debris from the wound. Cover the wound with sterile gauze dressing.
If the person is vomiting, roll the head, neck, and body as one unit to prevent choking. This still protects the spine, which you must always assume is injured in the case of a head injury. (Children often vomit ONCE after a head injury. This may not be a problem, but call a doctor for further guidance.)
Apply ice packs to swollen areas.
For a mild head injury, no specific treatment may be needed. However, closely watch the person for any concerning symptoms over the next 24 hours. The symptoms of a serious head injury can be delayed. While the person is sleeping, wake him or her every 2 to 3 hours and ask simple questions to check alertness, such as "What is your name?"