What does screening involve?

Screening primarily involves testing for the presence of a disease, which is crucial for early detection and intervention. This process typically aims to identify individuals who may have a disease even if they are not yet showing symptoms. For example, screening tests such as mammograms for breast cancer, Pap smears for cervical cancer, and blood tests for cholesterol levels are all designed to detect potential health issues before they become more serious.

Measuring blood pressure levels, while important in assessing cardiovascular health, is a part of routine monitoring rather than a distinct screening for a specific disease. Prescribing medications for symptoms is a treatment intervention rather than a screening process. Conducting surgeries for diagnosis is usually a diagnostic procedure that typically follows initial screening tests to confirm the presence of a disease. Thus, testing for the presence of a disease captures the essence of what screening entails, making it the correct answer.