How are individuals classified as having a known disease?

Individuals are classified as having a known disease when they have recognized cardiac, pulmonary, or metabolic diseases. This classification is based on established medical criteria that define specific conditions within these categories. For instance, recognized diseases in cardiology may include coronary artery disease or congestive heart failure, while pulmonary diseases might encompass chronic obstructive pulmonary disease (COPD) or asthma. Similarly, metabolic diseases include conditions like diabetes or thyroid disorders.

This classification does not rely solely on the presence of symptoms; many individuals with chronic diseases may be asymptomatic or may have only mild symptoms that do not fully reflect the underlying condition. It also does not depend exclusively on having a single primary risk factor. Instead, it is a comprehensive approach that identifies those who have a clinically recognized disease that may require monitoring or management, thereby highlighting the importance of a thorough medical diagnosis rather than superficial criteria.