If any of the following happen to you, see a doctor.
Any injury that leads to unconsciousness can indicate a concussion. Tests are needed to determine the extent of the damage.
A seizure can include involuntary jerking of the limbs, altered perception, unintentional staring, involuntary repeated muscle movements, or loss of consciousness. If you have a seizure and have not been diagnosed with epilepsy, see a doctor immediately. Brain aneurysms and tumors, both potentially life-threatening, are two possible causes of seizures.
Numbness, Tingling, or Paralysis
Numbness, tingling, or paralysis on one side of the body is one of the chief symptoms of stroke.
Find other causes of numbness.
Find other causes of tingling.
An extremely painful headache that comes on almost instantaneously can indicate a ruptured aneurysm or stroke.
Confusion or Forgetfulness
Repeatedly forgetting conversations or names, or misplacing objects is cause for concern. An occasional memory lapse is normal, but if it happens persistently, this might be an early symptom of dementia.