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 breathing difficulty, blue or grey lips, prolonged unresponsiveness, or a serious injury.
Emergency help is also needed if sleepiness has created immediate danger, such as repeated loss of control while driving.
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 prompt medical advice if you:
Fall asleep unexpectedly during conversations, meals, work, or other activities
Have repeated choking or gasping during sleep
Injure yourself or someone else during a sleep episode
Develop new dream-enactment behaviour, especially later in adulthood
Remain very sleepy despite treatment for a known sleep disorder
3
Does any of this apply?
Book an appointment
Arrange a routine appointment if sleep problems persist, interfere with daily life, or continue despite enough opportunity to sleep.
Assessment is also appropriate for loud habitual snoring with breathing pauses, repeated leg discomfort, unusual nighttime behaviour, or daytime sleepiness that is difficult to control.
Stop somewhere safe and arrange another way to travel.
The article also says
Do not drive if you feel at risk of falling asleep.
Every sign above is quoted from the sofidex article on Sleep disorders. If you are not sure, err upward — it is always reasonable to be checked.