Each disease is assigned an acuity: acute-severe (life-threatening), acute-moderate (not life-threatening), or subacute/chronic. The three levels of acuity are defined as follows:
acute-severe
The onset is acute, severe, and life threatening. The patient is likely to be admitted to the hospital.
acute-moderate
The onset is acute, but not life threatening. The patient is likely to seek medical attention, but not be admitted to the hospital.
chronic
The onset of symptoms is gradual over a period longer than 2 weeks (subacute) or 2 months (chronic).