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 if someone with possible low blood sugar:
Is unconscious, having a seizure, or cannot swallow safely
Remains severely confused after treatment
Does not improve promptly after glucagon
Has been injured or may have taken an overdose of diabetes medicine
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
Seek urgent same-day medical advice if episodes are repeated, are happening overnight, occur without warning, or continue despite following your treatment plan.
Prompt assessment is also appropriate after an unexplained episode if you do not take diabetes medicine.
3
Does any of this apply?
Book an appointment
Arrange routine follow-up if you are having occasional mild lows, need help identifying triggers, or are avoiding activities because of fear of hypoglycaemia.
Bring meter or continuous-monitor records if available.
The article also says
Place an unconscious person on their side if you can do so safely.
Give glucagon if it is available and you know how to use it.
Do not give anything by mouth.
Every sign above is quoted from the sofidex article on Low blood sugar. If you are not sure, err upward — it is always reasonable to be checked.