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 for vomiting blood, black tar-like stools with weakness or dizziness, fainting, severe sudden abdominal pain, or an inability to keep fluids down.
These can indicate major bleeding, a blockage, dehydration, or a hole in the stomach or bowel.
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 prompt medical assessment if you have:
Unexplained weight loss
Difficulty or pain when swallowing
Repeated vomiting
Ongoing unusual tiredness, weakness, or shortness of breath
Symptoms that continue despite usual indigestion treatment
And for anyone, someone who:
has abdominal pain that is severe, constant, or getting worse
is vomiting and cannot keep fluids down
3
Does any of this apply?
Book an appointment
Arrange a routine medical appointment if you have persistent or worsening indigestion, upper abdominal pain, reduced appetite, repeated nausea, or a new tendency to feel full quickly.
If you have been treated for stomach cancer, contact your cancer team between routine appointments if symptoms return, new symptoms persist, or treatment side effects are difficult to manage.
And for anyone, someone who:
has noticed a lump, a mole that has changed, or unexplained weight loss
Every sign above is quoted from the sofidex article on Stomach cancer. If you are not sure, err upward — it is always reasonable to be checked.