What type of sputum is typically associated with pneumonia?

The type of sputum typically associated with pneumonia is yellow/green. This coloration is often due to the presence of pus, which indicates a bacterial infection. In pneumonia, inflammation of the lung tissue can lead to the accumulation of white blood cells and cellular debris in the airways, resulting in sputum that has a thicker consistency and a yellow or green hue. The presence of bacteria in infected lungs can also contribute to this coloration, as the body's immune response generates exudate that is rich in these cells.

Other types of sputum mentioned are associated with different respiratory conditions. For instance, clear and watery sputum is more commonly seen in viral infections or allergies, while white and frothy sputum can be indicative of pulmonary edema. Rusty and thick sputum is typically associated with conditions like lobar pneumonia due to Streptococcus pneumoniae but is less common than yellow/green sputum. Thus, yellow/green sputum is the most characteristic finding in pneumonia, reflecting the infection and inflammation process occurring in the lungs.