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 care for:
Difficulty breathing at rest
Chest pain
Fainting or inability to stay awake
Confusion or severe weakness
A very fast heartbeat with dizziness
Very little or no urine
Rapidly worsening pallor or jaundice
For a baby or young child, emergency signs also include unusual limpness, difficulty waking, struggling to breathe, or being too weak to drink.
And for anyone, someone who:
has lips or skin that look pale, blue, grey or blotchy
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 you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek prompt medical assessment for unexplained red or brown urine, yellow skin or eyes, marked pallor, or a sudden loss of energy.
These symptoms have several possible causes and require testing.
If you have already been diagnosed with PCH, contact your healthcare team promptly if dark urine returns, tiredness worsens, fever persists, or you are passing less urine than usual.
3
Does any of this apply?
Book an appointment
These are reasons for earlier review, not just routine follow-up.
Every sign above is quoted from the sofidex article on Paroxysmal cold hemoglobinuria. If you are not sure, err upward — it is always reasonable to be checked.