What does pyorrhea refer to?

Pyorrhea refers specifically to a discharge of purulent matter, typically associated with advanced gum disease known as periodontitis. In this condition, the gums become inflamed and infected, leading to the formation of pus as a response to the infection. This purulent discharge can be evacuated during dental examinations and is a clear indicator of significant dental health issues.

The other options relate to different medical conditions that do not fit the definition of pyorrhea. An increase in heart rate pertains to tachycardia, a different physiological response. A type of skin infection would be more accurately described using terms like abscess or cellulitis. Inflammation of the lungs, known as pneumonia, involves a completely distinct pathology.