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 for:
A seizure, especially a first seizure or one lasting several minutes
New weakness, facial drooping, difficulty speaking, or loss of balance
Increasing drowsiness, confusion, collapse, or difficulty waking
A sudden severe headache or repeated forceful vomiting
Worsening symptoms after a head injury
Fever with severe headache, neck stiffness, confusion, or a seizure
These symptoms are not always an emergency, but they may justify an earlier examination or scan.
Routine follow-up is appropriate when symptoms are stable or improving and no emergency signs are present.
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 baby needs urgent assessment for a seizure, marked sleepiness, difficulty waking, a tense or bulging soft spot, repeated vomiting, breathing changes, or poor feeding with signs of illness.
Contact your usual medical team promptly if known symptoms are becoming more frequent, headaches are steadily worsening, or vomiting, balance problems, behaviour changes, or new memory difficulties develop.
3
Does any of this apply?
Book an appointment
Keep planned appointments so that recovery and any imaging findings can be reviewed.
Every sign above is quoted from the sofidex article on Subdural effusion. If you are not sure, err upward — it is always reasonable to be checked.