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 sudden, very severe headache
New weakness, numbness, facial drooping, or trouble speaking
A seizure, fainting, severe confusion, or difficulty waking
New vision loss, severe balance problems, or inability to walk
Catheter-site bleeding that does not stop with firm pressure
Do not drive yourself for emergency care.
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
Seek prompt medical advice for increasing pain, fever, wound redness or drainage, a growing catheter-site lump, repeated vomiting, or a new rash after starting medicine.
The article also says
Contact your team about medication questions, persistent tiredness, delayed recovery, or a stable incision or catheter-site bruise.
Every sign above is quoted from the sofidex article on Brain aneurysm repair. If you are not sure, err upward — it is always reasonable to be checked.