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
Go to an emergency department after a major injury if the leg looks deformed, appears shorter than usual, or becomes pale, cold, numb, or difficult to move.
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 same-day medical care if your child:
Has hip or leg pain with fever
Cannot stand or put weight on the leg
Has severe or rapidly worsening pain
Has a hot, swollen, or red joint
Appears unusually sleepy, weak, or generally unwell
Has new hip, thigh, or knee pain with an outward-turned leg
And for anyone, someone who:
has abdominal pain that is severe, constant, or getting worse
3
Does any of this apply?
Book an appointment
Arrange a routine appointment if the pain or limp is not clearly improving after a few days, lasts about a week, keeps returning, or wakes your child from sleep.
Your child should also be assessed if stiffness persists, normal activities remain limited, or you are unsure what caused the pain.
Every sign above is quoted from the sofidex article on Hip pain in children. If you are not sure, err upward — it is always reasonable to be checked.