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:
Severe confusion, a seizure, or loss of consciousness
Low glucose that cannot be treated safely by mouth
Trouble breathing or swelling of the face, tongue, or throat
Signs of diabetic ketoacidosis, such as vomiting, deep breathing, and marked drowsiness
If glucagon has been prescribed and someone has been trained to use it, they should follow its instructions while emergency help is called.
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 for persistent vomiting, rising glucose that is not responding to your plan, or moderate to high ketones.
Follow your sick-day plan while arranging help.
3
Does any of this apply?
Book an appointment
Arrange routine contact if you have repeated low readings, frequent unexplained high readings, leaking injections, painful or lumpy sites, or difficulty seeing or operating your device.
Contact the team if illness, fasting, travel, shift work, or pregnancy changes your usual schedule.
The article also says
A person who is unconscious should not be given food or drink.
Every sign above is quoted from the sofidex article on Giving insulin shots to adults. If you are not sure, err upward — it is always reasonable to be checked.