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
Get emergency help for:
Dark brown or cola-coloured urine with muscle pain or weakness
Passing very little urine
New difficulty breathing or swallowing
Severe or rapidly spreading weakness
Chest pain, fainting, or a fast or irregular heartbeat
These symptoms can indicate severe muscle breakdown or involvement of breathing or heart muscles.
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 advice the same day if symptoms are rapidly worsening or if weakness is making it hard to walk safely.
They need prompt assessment rather than waiting for a routine appointment.
3
Does any of this apply?
Book an appointment
Arrange a routine medical review if you develop persistent muscle aching, cramps, or weakness after starting or changing a medicine.
Mention if ordinary tasks such as climbing stairs, rising from a chair, or lifting your arms have become difficult.
Every sign above is quoted from the sofidex article on Pharmacogenic myopathy. If you are not sure, err upward — it is always reasonable to be checked.