Head injury refers to an injury to the head caused by external forces, such as falls, traffic accidents, falling objects, or falls from a height.

After a head injury, you may have a mild concussion or other complications. Common symptoms include a mild headache, dizziness, nausea, vomiting, drowsiness, and temporary memory loss. Older adults, patients who cannot express their symptoms, and young children should be examined by a doctor promptly if they become unusually irritable or cannot be comforted.

1. Continuous observation:
   Stay with the patient during the first 24 hours and check on the patient every hour. Wake the patient every 2-4 hours. Do not leave the patient alone for the first 48 hours. Continue observing the patient for 3-7 days.
   
2. Diet and Medication
   1. During the first 2 days after the injury, avoid foods or medications that may affect your level of consciousness, such as sedatives, sleeping pills, and alcohol.
   2. Do not take over-the-counter medicines or Chinese herbal medicines without your doctor's advice. 
   3. If you are taking anticoagulants (such as aspirin or clopidogrel) or any other medications you are concerned about, consult your doctor before taking them.   
3. If you have the following conditions, please go to the emergency department immediately:
   
   1. Persistent dizziness, vomiting, or worsening headache that cannot be improved after resting.
   2. Altered state of consciousness, e.g. drowsiness, nonresponsive, or slurred speech.
   3. Seizure (involuntary muscle contractions).
   4. Fever combined with a stiff neck and pain.
   5. Blurred vision or seeing distorted objects.
   6. Weakness in body or limbs, numbness sensation, or unsteady gait.
   7. Urinary or bowel incontinence.