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
Seek same-day assessment in an emergency department if you develop new or worsening nasal blockage, internal swelling, or increasing pain after an injury or nasal procedure.
Call emergency services for:
Serious difficulty breathing
Heavy bleeding that does not stop with first aid
Loss of consciousness, confusion, or a seizure after an injury
Severe headache with vomiting, neck stiffness, or unusual drowsiness
Rapidly increasing swelling around the eyes or changes in vision
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
Do not wait for a routine appointment, and do not try to drain the swelling yourself.
Urgent assessment is also needed for fever, pus-like discharge, worsening facial swelling, or symptoms that return after a hematoma has been drained.
3
Does any of this apply?
Book an appointment
Routine follow-up is appropriate after treatment when symptoms are stable or improving.
Keep the arranged appointments even if the nose feels better, because an early recurrence may not be obvious.
Every sign above is quoted from the sofidex article on Nasal septal hematoma. If you are not sure, err upward — it is always reasonable to be checked.