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 chest pressure or pain, severe shortness of breath, fainting, or sudden sweating with nausea.
Also treat sudden facial drooping, arm weakness, speech difficulty, loss of balance or a sudden severe headache as possible stroke symptoms.
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
Arrange a routine or prompt medical appointment for:
A new lump, swelling or persistent unexplained pain
A changing mole or pigmented skin area
A wound that is not healing
Increasing thirst, urination, fatigue or unexplained weight change
New vision problems
Worsening walking difficulty, joint stiffness or falls
New concerns about fertility, mood or daily function
Seek urgent medical care for a wound that becomes rapidly more painful, red, swollen or warm, especially with pus or fever.
These can be signs of a serious infection.
Sudden loss of vision, a severe injury after a fall or uncontrolled bleeding also requires urgent assessment.
Every sign above is quoted from the sofidex article on Premature senility syndrome. If you are not sure, err upward — it is always reasonable to be checked.