Which term best describes a long-standing medical condition?

The term that best describes a long-standing medical condition is "chronic." A chronic condition is one that persists over a long period of time, often for months or even years. These conditions typically require ongoing management and can affect an individual’s quality of life. Examples of chronic conditions include diabetes, hypertension, and arthritis.

In contrast, an acute condition arises suddenly and is typically severe in nature, but it often resolves with treatment. The term subacute refers to a stage of illness that is between acute and chronic, representing a timeframe that is not as brief as acute but not as long-standing as chronic. Progressive refers to conditions that are characterized by a gradual worsening or advancement over time, but it doesn't specifically denote the duration of a condition in the same way that chronic does. Thus, for conditions that are long-lasting and often require continuous care, chronic is the most appropriate term.