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 the person:
Cannot breathe, speak, or cough effectively
Has severe breathing difficulty or blue-grey lips
Collapses or becomes unresponsive
Is choking on a pencil or pencil fragment
If the swallowing was deliberate and there is an immediate risk of further self-harm, seek emergency mental health support and stay with the person if it is safe to do so.
And for anyone, someone who:
you believe has taken an overdose or swallowed something poisonous
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
2
Is any of this happening?
Be seen today
Seek urgent medical assessment after swallowing a whole pencil, a sharpened pencil, a long section, or a splintered piece.
Do this even if there are no symptoms.
Urgent assessment is also needed for:
Trouble swallowing or inability to swallow saliva
Neck, chest, or abdominal pain
Repeated vomiting
Blood in vomit or stool
Fever, a swollen abdomen, or increasing tenderness
Coughing or wheezing that began during the event
Uncertainty about what was swallowed
3
Does any of this apply?
Book an appointment
Routine follow-up may be enough after the object’s size and shape have been assessed.
The article also says
Use age-appropriate choking first aid if you are trained to do so.
Do not put fingers into the mouth unless you can clearly see and safely grasp the object.
If a very small, blunt piece was swallowed and there are no symptoms, contact a healthcare service or poison information centre for case-specific advice.
Every sign above is quoted from the sofidex article on Pencil swallowing. If you are not sure, err upward — it is always reasonable to be checked.