The most common pathogenic bacteria of bacterial pneumonia is Streptococcus pneumoniae, also known as pneumococcus. Clinical manifestations have an acute onset, with high fever, chills, cough, coughing up bloody sputum, chest pain and chest tightness as typical symptoms. X-rays or CT of both lungs can see solid changes of acute inflammation in lung segments and lobes, and may appear to have rust-colored sputum coughing up. Pathological changes mainly include typical congestion phase, red hepatomegaly phase, gray hepatomegaly phase, and dissipation phase. Streptococcus pneumoniae itself does not produce toxins and does not cause necrosis of the lung tissue or the formation of cavities, leaving no traces after cure. If treated with antibiotics, about 10% of patients may have pneumothorax and other extrapulmonary infections. The current treatment of choice is penicillin, which is effective in killing Streptococcus pneumoniae for 14 days.