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 assessment rather than assuming these symptoms are caused by ordinary thrush.
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 care for difficulty or significant pain when swallowing, dehydration, rapidly spreading redness, severe swelling or worsening illness in someone with a weakened immune system.
And for anyone, someone who:
has a fever with a stiff neck, a rash that does not fade under pressure, or severe headache
has a wound that is hot, spreading red, or leaking pus
3
Does any of this apply?
Book an appointment
Arrange routine medical advice if:
This is your first suspected yeast infection
Symptoms are different from previous confirmed infections
Treatment has not helped or symptoms soon return
Infections occur repeatedly
You have diabetes or a weakened immune system
You are pregnant or breastfeeding
There is a strong-smelling, green, yellow or bloody discharge
You have sores, blisters, pelvic pain or concern about a sexually transmitted infection
Oral thrush makes eating uncomfortable or keeps returning
The article also says
Fever, chills, confusion, faintness or trouble breathing can indicate a serious infection, particularly after major surgery or during hospital care, or if you have a central intravenous line.
Every sign above is quoted from the sofidex article on Yeast infections. If you are not sure, err upward — it is always reasonable to be checked.