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 now if someone:
Cannot breathe, speak, cry, or cough effectively
Has a silent or very weak cough during choking
Develops blue or grey lips or skin
Becomes confused, very drowsy, or unconscious
Has severe or rapidly worsening breathing difficulty
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 urgent medical assessment after a witnessed or strongly suspected inhalation if coughing, wheezing, noisy breathing, chest discomfort, or shortness of breath continues.
A child who had a clear choking episode should be assessed promptly if there is any concern that the object was not expelled, even if they now appear comfortable.
3
Does any of this apply?
Book an appointment
Arrange follow-up after treatment if fever, increasing cough, unpleasant-smelling mucus, breathing difficulty, or chest pain develops.
These symptoms may indicate infection, a remaining fragment, or another complication.
Routine follow-up may also be advised after bronchoscopy or pneumonia.
Keep these appointments even if symptoms have improved.
The article also says
Give appropriate choking first aid while help is coming.
Do not delay the call while trying to retrieve an object.
Every sign above is quoted from the sofidex article on Foreign object - inhaled. If you are not sure, err upward — it is always reasonable to be checked.