Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call emergency services after a head injury if someone:
Cannot be woken or becomes increasingly difficult to wake
Has a seizure
Develops weakness, numbness or poor coordination
Has trouble speaking or becomes confused
Has one pupil larger than the other
Has a worsening severe headache or repeated vomiting
Loses consciousness or has worsening symptoms after seeming well
Has clear fluid or significant bleeding from the nose or ear
A healthcare service can advise whether emergency assessment is needed.
After treatment, seek emergency help for a new seizure, loss of consciousness, increasing confusion, new weakness, repeated vomiting or a rapidly worsening headache.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Prompt assessment is also important after a head injury for someone taking an anticoagulant or who has a bleeding disorder, even when symptoms seem mild.
3
Does any of this apply?
Book an appointment
Contact the follow-up team routinely about symptoms that are stable but not improving, wound concerns or difficulties returning to everyday activities.
The article also says
Keep the person still if a neck injury is possible.
Do not give food or drink, and do not leave them alone while waiting for help.
Every sign above is quoted from the sofidex article on Epidural hematoma. If you are not sure, err upward — it is always reasonable to be checked.