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 help now for:
New or severe chest pressure, tightness, heaviness, or pain
Chest discomfort with sweating, nausea, breathlessness, or faintness
Discomfort spreading to an arm, back, neck, jaw, or upper abdomen
Severe difficulty breathing, especially at rest
Collapse, unresponsiveness, or absent or abnormal breathing
Sudden weakness, facial droop, speech difficulty, or loss of vision
Call your local emergency number.
And for anyone, someone who:
has chest pain, tightness or pressure lasting more than a few minutes
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
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
Get urgent medical advice for chest symptoms that are new, happen with less activity than usual, last longer, or are becoming more frequent.
Also seek urgent advice for fainting during exercise, a sustained rapid heartbeat with dizziness, or rapidly worsening breathlessness or swelling.
And for anyone, someone who:
is getting rapidly more short of breath, or has gained several pounds in a few days with swelling
3
Does any of this apply?
Book an appointment
Arrange a routine appointment for recurring palpitations, gradually reduced exercise tolerance, mild ankle swelling, or breathlessness that is not sudden.
These symptoms have many possible causes, but they should not be ignored.
Report a clear change from your usual pattern rather than waiting for the next planned review.
The article also says
Do not drive yourself if you may be having a heart attack or stroke.
If you already have a heart condition, follow the action plan provided by your care team.
Every sign above is quoted from the sofidex article on Heart disease. If you are not sure, err upward — it is always reasonable to be checked.