Tertiary prevention is needed in which stage of the natural history of disease?

• A. Pre-pathogenesis
• B. Pathogenesis
• C. Predromal
• D. Terminal

Answer: (D)

Tertiary prevention focuses on reducing disability and preventing complications after a disease has already developed, with goals like rehabilitation, functional improvement, and maintaining quality of life. In the natural history of disease, this stage is reached once illness is established and the patient may enter an end-stage or terminal phase where the focus shifts from curing the disease to preventing further harm and preserving comfort. That’s why the terminal stage is the best fit for tertiary prevention, as interventions aim to prevent complications (like infections or bed ulcers) and improve or maintain function and well-being despite advanced disease.

Earlier stages—before disease starts (pre-pathogenesis), during the disease development (pathogenesis), or in the prodromal/subclinical period—are typically addressed by primary or secondary prevention, not tertiary.