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
Seek emergency help for:
Severe breathing difficulty, confusion, collapse, or loss of consciousness
A seizure or hypoglycemia that cannot be treated safely
Suspected DKA, including vomiting, stomach pain, deep breathing, dehydration, or fruity-smelling breath
Very high glucose with marked thirst, weakness, drowsiness, or confusion
Symptoms of a heart attack or stroke
Use prescribed emergency hypoglycemia treatment if available and you are trained to use it, and call emergency services.
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
If you have diabetes, contact your care team promptly if readings are repeatedly outside your agreed range, hypoglycemia becomes more frequent, you are vomiting, or you cannot keep fluids down.
New numbness or a foot blister, broken skin, redness, swelling, or warmth also needs timely assessment.
3
Does any of this apply?
Book an appointment
Arrange a routine appointment for persistent thirst, frequent urination, unexplained weight loss, blurred vision, recurrent infections, or slow-healing wounds.
Testing is also appropriate if you have risk factors without symptoms.
The article also says
Do not give food or drink to an unconscious person because they could choke.
Every sign above is quoted from the sofidex article on Diabetes. If you are not sure, err upward — it is always reasonable to be checked.