The term "poor prognosis" refers to a negative or unfavorable outlook for someone's health, often indicating that their condition is likely to worsen or become more difficult to treat. This can be due to various factors such as the severity of the illness, the patient's age, overall health and response to treatment. A poor prognosis does not necessarily mean that a person will definitely experience a decline in their health, but it does suggest that they may face greater challenges than someone with a better outlook.