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
Get emergency help if you or the affected person:
Faints, becomes confused, or is very difficult to wake
Has severe weakness with little or no urine
Cannot keep fluids down and is becoming rapidly more unwell
Develops signs of shock, such as cold clammy skin or very fast breathing
Has severe abdominal pain with a rigid or markedly swollen abdomen
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 if you have bloody diarrhea, persistent vomiting, worsening stomach pain, or signs of dehydration.
You should also seek advice if symptoms are not beginning to improve after several days.
3
Does any of this apply?
Book an appointment
After the diarrhea has settled, arrange routine medical review for new joint swelling, ongoing bowel changes, unexplained weight loss, or symptoms that keep returning.
The article also says
Contact a healthcare professional early if symptoms affect a baby, an older adult, someone who is pregnant, or a person with a weakened immune system or major long-term condition.
These groups may need closer assessment even when symptoms initially seem mild.
Every sign above is quoted from the sofidex article on Salmonella enterocolitis. If you are not sure, err upward — it is always reasonable to be checked.