ABSTRACT
Diagnosis is the art of identifying a clinical condition from its signs and symptoms. A sign is the effect of a disease that can be observed by someone else, for example, coughing, sneezing, rise in body temperate, and so on. Whereas symptoms are effects experienced only by the person who has the condition, for example, headache, the feeling of the tightness in the chest, muscular pain, severe weakness, and so on. Laboratory diagnostic procedures may be used to ensure active infection in clinically suspected patients or they can be used to learn about past infections. Instances may arise where the signs and symptoms overlap with other non-COVID illnesses, in such scenarios, differential diagnosis becomes very important. The clinical assessment of patients admitted with a possible influenza-like illness should begin with a thorough investigation of their vital signs through physical examination.
