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 for:
New difficulty breathing or swallowing
Rapidly worsening weakness affecting several limbs
Fainting with ongoing severe dizziness or an abnormal heartbeat
Sudden one-sided weakness, facial drooping, or speech difficulty
Emergency assessment should not be delayed.
And for anyone, someone who:
has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
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 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 if symptoms are spreading quickly, weakness is getting noticeably worse, you are falling, or you develop new bladder or bowel problems.
A red, hot, swollen, infected, or open wound on a numb foot also needs prompt attention, particularly if you have diabetes.
And for anyone, someone who:
has a new severe headache unlike any they have had before
3
Does any of this apply?
Book an appointment
Arrange a routine medical appointment if you have persistent or recurring numbness, tingling, burning pain, unexplained weakness, or balance problems.
Earlier assessment may identify a treatable cause and help protect numb areas from injury.
The article also says
Sudden one-sided symptoms may be caused by a stroke rather than peripheral neuropathy.
Every sign above is quoted from the sofidex article on Peripheral neuropathy. If you are not sure, err upward — it is always reasonable to be checked.