What is the purpose of a differential diagnosis?

• A. List of potential problems
• B. A single definitive diagnosis
• C. A treatment plan
• D. A prognosis estimate

Answer: (A)

When you first evaluate a patient, you generate a list of plausible causes that could explain their signs and symptoms. This approach keeps you from sticking to one assumption too early and helps you consider dangerous possibilities that must be ruled in or out.

This differential diagnosis structure guides what information to gather, which tests to order, and how to prioritize treatments in the moment. It’s about thinking through multiple potential problems, especially life‑threatening ones, so you don’t miss something critical. For example, chest pain can stem from heart attack, pulmonary embolism, aortic dissection, pneumothorax, or GI issues; keeping these possibilities in mind informs how you assess the patient, what monitoring and diagnostics you pursue, and how you decide on initial management.

A single definitive diagnosis, a fixed treatment plan, or a prognosis estimate typically comes later as you collect data and observe the patient’s response. The purpose here is to map out potential problems first, ensuring a thorough and safe evaluation.