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
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 care if:
You cannot put weight on the foot after an injury
The foot or ankle is badly swollen, bruised, or misshapen
The heel becomes red, hot, and swollen, especially with fever
You felt a sudden snap and developed bruising or severe pain
The foot becomes pale, blue, cold, or suddenly numb
These are not typical signs of uncomplicated plantar fasciitis and may indicate an injury, infection, or circulation problem.
3
Does any of this apply?
Book an appointment
Arrange a routine appointment if the pain is affecting normal activities, keeps returning, or has not begun to improve after several weeks of self-care.
Earlier assessment is sensible if you have diabetes, reduced feeling in your feet, poor circulation, or a condition affecting your immune system.
The article also says
You should also seek medical advice if you have numbness, tingling, pain at rest or during the night, pain in both heels with joint stiffness elsewhere, or symptoms that do not match the usual first-step pattern.
Every sign above is quoted from the sofidex article on Plantar fasciitis. If you are not sure, err upward — it is always reasonable to be checked.