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 breathing is severely difficult, chest pain is intense or persistent, the person collapses, or they are difficult to wake.
These signs can occur with a major blood clot, dangerously low oxygen, or acute right-heart failure.
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 help for:
New or rapidly worsening breathlessness
New chest pain or pressure
Fainting or nearly fainting
Coughing up blood
A new fast or irregular heartbeat with weakness or breathlessness
Marked drowsiness, confusion, or blue or grey lips
Sudden swelling or pain in one leg, especially with breathlessness
3
Does any of this apply?
Book an appointment
Arrange a routine review if breathlessness is gradually worsening, normal activities are becoming harder, or swelling is increasing.
Also seek advice for repeated dizziness, a persistent racing heartbeat, reduced appetite caused by abdominal swelling, or rapid weight gain that may indicate fluid retention.
Every sign above is quoted from the sofidex article on Cor pulmonale. If you are not sure, err upward — it is always reasonable to be checked.