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 or go to an emergency department now if:
Bleeding is heavy, spurting, or does not stop with firm direct pressure
The wound is very deep, gaping, or exposes fat, muscle, tendon, or bone
A large or deeply embedded object remains in place
Part of the body has been partly or completely cut off
The injury involves the eye, neck, chest, abdomen, or a major blood vessel
The area becomes pale, blue, cold, numb, weak, or difficult to move
The wound came from high-pressure equipment or moving machinery
Apply pressure around it, keep it as still as possible, and seek emergency help.
And for anyone, someone who:
is bleeding heavily and it will not stop with firm pressure
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 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
Arrange prompt, same-day medical advice for a deep puncture, nail-through-shoe injury, bite, contaminated wound, or cut that may need closing.
Also seek prompt care if your tetanus vaccination history is incomplete or uncertain, or if the injury could involve rabies.
Contact a healthcare professional promptly if redness spreads, pain or swelling increases, pus appears, the wound develops a bad smell, red streaks extend from it, or you develop a fever or feel unwell.
And for anyone, someone who:
has a wound that is hot, spreading red, or leaking pus
3
Does any of this apply?
Book an appointment
Routine follow-up is appropriate for dressing checks, stitch or staple removal, scar concerns, or mild symptoms that are improving as expected.
The article also says
Do not remove a large embedded object.
It may be limiting bleeding.
Every sign above is quoted from the sofidex article on Cuts and puncture wounds. If you are not sure, err upward — it is always reasonable to be checked.