Patient  Clinical findings  CT (imaging findings of pneumonia)  Organ damage
Mild  Negative  None  None
No dyspnea, with or without cough, fever <38°C (quelled without treatment)
No history of chronic respiratory disease
Moderate  dyspnea, with or without cough  Multifocal patchy GGOs with subpleural distribution  None
SpO2 >93% without oxygen inhalation
Severe  Fever  Diffuse heterogeneous consolidation with GGO,  None
Muscle ache  Rapid progression (>50%) on CT imaging within 24–48 hr
Headache
Confusion
Respiratory distress:
RR ≥ 30 times/min
SpO2 < 93% at rest
PaO2/FiO2 ≤ 300 mmHg
Critical  Shock   “Extra pulmonary” organ failure or MODS
Respiratory failure
need mechanical assistance
Intensive care unit is needed