Pneuma are referred to frequently in the Hippocratic corpus as the life-giving vapors which are taken in through the lungs and distributed throughout the body. The latter causes fever, tachycardia, hypotension, leukocytosis and in certain cases all the sequelae of septic syndrome. When a previously healthy patient presents with all of the above, and most particularly with the characteristic rusty sputum suggesting the pneumococcus, the physician should have little trouble making the diagnosis. However, in immunocompromised patients, patients already on ventilators, patients with a history of heart failure, etc., the picture may be murky. Dyspnea is certainly much less specific, and many patients with pneumonia do not complain specifically of this.
Historical clues are of great benefit.
During my military service, I encountered a young man with a puzzling constellation of fever, dyspnea with interstitial infiltrates, cytopenias and proteniuria. Part of the community.