A concussion can be followed by a brief loss of consciousness, retrograde amnesia, and may be accompanied by dizziness and headache. When a concussion occurs, there may be a transient loss of consciousness, which can last for several minutes and usually lasts less than 30 minutes. Patients may also experience retrograde amnesia, which is the inability to remember what happened at the time of the injury or in the recent past. In addition, patients may experience dizziness, headache, ringing in the ears, insomnia, emotional instability, and in some cases, pallor, cold sweats, and a drop in blood pressure. Concussion generally has a good prognosis and does not require special treatment, and will gradually recover through rest. However, it is recommended that patients with suspected concussions should seek medical attention in time, and be actively treated by doctors through a series of examinations to rule out other diseases and confirm the diagnosis of concussion.