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 vomiting blood, coughing up a significant amount of blood, sudden severe headache, collapse, confusion, new weakness on one side, trouble speaking, or serious difficulty breathing.
Chest pressure, sudden stroke symptoms, or other signs of a possible heart attack or stroke are emergencies even while you are taking aspirin.
Do not drive yourself for emergency care.
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 advice for:
Red or black, tar-like stools
Blood in the urine
A nosebleed that will not stop with firm pressure
New weakness, unusual tiredness, or shortness of breath that could suggest anaemia
Persistent or severe stomach pain
3
Does any of this apply?
Book an appointment
And for anyone, someone who:
is having side effects from a medicine, or is struggling to take it as prescribed
The article also says
Contact your healthcare team routinely if you develop persistent indigestion, frequent nosebleeds, troublesome bruising, or bleeding gums.
Also contact them before starting another pain medicine or supplement.
Every sign above is quoted from the sofidex article on Low-dose aspirin therapy. If you are not sure, err upward — it is always reasonable to be checked.