Progressive disease

Progressive disease or progressive illness is a disease or physical ailment whose course in most cases is the worsening, growth, or spread of the disease. This may happen until death, serious debility, or organ failure occurs.^[1] Some progressive diseases can be halted and reversed by treatment (surgical, dietary, or lifestyle interventions). Many can be slowed by medical therapy. Some cannot be altered by current treatments.^[2]

Though the time distinctions are imprecise, diseases can be rapidly progressive (typically days to weeks) or slowly progressive (months to years). The time course of a disease affects whether it is considered acute or chronic. By definition, virtually all slowly progressive diseases are also chronic diseases. Biologically, many of these are also referred to as degenerative diseases due to the cellular changes.^{[citation needed]}

Not all chronic diseases are progressive: a chronic, non-progressive disease may be referred to as a static condition.

Progressive disease can also be a clinical endpoint i.e. an endpoint in a clinical trial. A progressive disease should not be confused with a terminal disease, the difference being that a terminal disease invariably leads to death.