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 or go to an emergency department if abdominal pain is severe or sudden, particularly if you also:
Faint, feel very weak, become confused, or have trouble breathing
Have chest pressure or pain spreading to your chest, jaw, or arm
Vomit blood or material resembling coffee grounds
Pass black, tar-like stool or a large amount of blood
Have a rigid, very swollen, or extremely tender abdomen
Cannot pass stool or gas and have swelling with vomiting
Could be pregnant and have severe pain, heavy bleeding, or faintness
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 same-day medical advice if the pain is worsening or comes with fever, repeated vomiting, dehydration, yellow skin or eyes, blood in urine or stool, or difficulty urinating.
You should also seek prompt advice for persistent one-sided pain or bleeding during pregnancy.
And for anyone, someone who:
has abdominal pain that is severe, constant, or getting worse
3
Does any of this apply?
Book an appointment
Book a routine appointment if pain lasts several days, keeps returning, wakes you regularly, affects eating or daily activities, or comes with unexplained weight loss or a lasting change in bowel habits.
The article also says
Young children, older adults, and people with weakened immune systems may show less typical symptoms.
If you are concerned that someone is becoming more unwell, seek advice.
Every sign above is quoted from the sofidex article on Abdominal pain. If you are not sure, err upward — it is always reasonable to be checked.