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 sudden excessive yawning occurs with:
Weakness or numbness on one side
A drooping face or difficulty speaking
A sudden, severe headache
New confusion, loss of balance, or vision loss
Chest pain, severe breathing difficulty, or collapse
A seizure or inability to wake normally
These symptoms need emergency assessment whether or not yawning is present.
Do not drive yourself if you may be having a stroke, heart emergency, or seizure.
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 same-day medical advice if frequent yawning starts suddenly with persistent dizziness, repeated near-fainting, a new headache, or a recent medicine change.
Get prompt help if sleepiness makes driving, operating equipment, or staying awake unsafe.
3
Does any of this apply?
Book an appointment
Book a routine appointment if yawning continues for several days or weeks, keeps returning, or disrupts daily life.
Arrange a review if you have loud snoring, witnessed pauses in breathing during sleep, unrefreshing sleep, or strong daytime sleepiness.
Every sign above is quoted from the sofidex article on Excessive yawning. If you are not sure, err upward — it is always reasonable to be checked.