Endemic describes a disease or condition that is consistently present within a specific geographic area or population, at a baseline level that persists over time. It does not speak to how severe or how many people are affected, but rather to the disease's steady presence in that place or group.

Key nuances:

• Endemic vs epidemic vs pandemic: endemic means regular, baseline presence in a region; an epidemic is a sudden increase in cases in a region; a pandemic is a disease spreading across countries or continents.

• Examples help clarify: malaria is not endemic in the United Kingdom due to lack of transmission, whereas chickenpox is endemic there because cases occur at a relatively stable level year to year.

• In epidemiology, endemic can also describe a disease that is constantly present but at varying levels (hyperendemic or hypoendemic depending on intensity).

If you’d like, I can tailor this explanation to a specific disease or region you’re studying.