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 rather than driving if the injured person is unconscious, difficult to wake, having a seizure, or becoming less responsive.
Avoid unnecessary movement of the head and neck.
Seek emergency help for:
Worsening confusion, agitation, or unusual behavior
Increasing sleepiness or difficulty waking
Repeated vomiting or a severe, worsening headache
Weakness, numbness, poor coordination, or trouble speaking
Unequal pupils or new vision problems
Blood or clear fluid leaking from an ear or the nose
Bruising behind an ear or around both eyes
A visible dent, open skull wound, or object in the wound
A seizure, collapse, or breathing difficulty
Emergency assessment is also important after a significant head injury if the person takes blood-thinning medicine or has a bleeding disorder.
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
A suspected skull fracture after a recent head injury needs urgent assessment.
Return for urgent reassessment if symptoms worsen rather than improve.
3
Does any of this apply?
Book an appointment
After discharge, arrange routine follow-up if headache, dizziness, sleep problems, memory changes, low mood, hearing changes, or difficulty returning to normal activities continue.
Every sign above is quoted from the sofidex article on Skull fracture. If you are not sure, err upward — it is always reasonable to be checked.