Final answer:
A chronic illness typically results in a permanent deviation from normal and may last for an extended period without a consistent, predictable clinical course. They can start without an acute phase and can vary in presentation and severity over time.
Step-by-step explanation:
A characteristic of a chronic illness is that it:
- results in permanent deviation from normal
Chronic diseases are long-term health conditions that may last for months or years and are generally incurable. These diseases, such as type 1 diabetes, cardiovascular diseases, and certain infectious diseases like herpes and AIDS, persist over time. It's important to distinguish chronic diseases from acute diseases, which are short-lived and either resolve quickly or lead to rapid death.
Chronic diseases often do not have a consistent predictable clinical course as they can fluctuate and present with varying symptoms and severity over time. Furthermore, they do not always start with an acute illness and progress slowly; some chronic diseases may begin insidiously without initial acute presentation.