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:
A first seizure or a seizure lasting unusually long
Sudden weakness, facial drooping, confusion, or trouble speaking
Sudden loss of vision
Bleeding that does not stop with firm, continuous pressure
These symptoms are uncommon and are not expected with an uncomplicated skin-only port-wine stain.
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 new eye pain, a red eye with headache or nausea, or a sudden change in vision.
These symptoms can be related to increased pressure in the eye.
3
Does any of this apply?
Book an appointment
Arrange a routine medical assessment if a birthmark may be a port-wine stain, particularly if it covers the forehead, eyelid, or a large part of the face.
A stain associated with limb swelling, enlarged veins, or unequal limb growth also deserves assessment.
Make an appointment if the mark becomes noticeably thicker, develops a new lump, repeatedly bleeds, or starts causing pain.
Changes may be treatable and do not automatically mean something serious.
Every sign above is quoted from the sofidex article on Port-wine stain. If you are not sure, err upward — it is always reasonable to be checked.