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
Use emergency services if there is immediate danger.
This includes:
An intention or plan to die, self-harm, or harm someone else
Voices ordering the person to do something dangerous
Severe agitation, aggression, or behavior that cannot be kept safe
Collapse, seizure, fever, serious head injury, overdose, or suspected poisoning
Sudden severe confusion or rapidly changing alertness
Psychotic symptoms soon after childbirth, especially with confusion, extreme energy, little sleep, or thoughts of harm
Postpartum psychosis is a medical emergency because symptoms can change quickly.
Do not leave the affected person alone with the baby while emergency help is being arranged.
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
Arrange a prompt medical or mental health assessment for new hallucinations, fixed unusual beliefs, marked suspiciousness, disorganized behavior, or a clear decline in everyday functioning.
A first episode should be assessed even if the person does not seem distressed.
Seek urgent same-day help if symptoms are getting worse quickly, the person is not eating or drinking, has gone several nights with little sleep, is wandering or behaving unsafely, or cannot care for basic needs.
The article also says
If you are supporting someone, speak calmly and acknowledge their fear or distress.
You do not need to agree with a delusion, and forceful arguments may increase distress.
Focus on immediate safety and obtaining professional help.
Every sign above is quoted from the sofidex article on Psychosis. If you are not sure, err upward — it is always reasonable to be checked.