This is sometimes called ‘acute confusional state’.
It would be highly unusual to see delirium outside of a hospital setting. It is a medical emergency.
There is usually fluctuating consciousness. There may be disorientation. There is often delusional and challenging behaviour.
There are usually physical signs such as fast heart rate, fluctuating blood pressure, possible fever, sweating, sleep disturbance. There may be tremor or seizures.
Psychiatrists are often called to manage some of the behavioural problems of delirium in the hospital setting.
The essence of management is medical support with hydration and rapidly finding the cause. Once found the cause needs to be treated, such as infection (sepsis), pneumonia, adverse drug reaction/drug withdrawal.
I would certainly recognise when a patient has a medical emergency, be it delirium, neuroleptic malignant syndrome, serotonin syndrome or many others. It is unlikely that such a diagnosis would arise first in a private clinic.