Sometimes, diagnosing patients is pretty easy, but other times... not so much. Luckily, in a medical setting we have tools that can help us figure out what's wrong with patients, and how to help them. In this episode of Crash Course Outbreak Science, we'll use clinical symptomatology and diagnostic testing to collect data and test our hypotheses about what may be wrong with some hypothetical patients, and use what we learn to help our patients get better and stop the disease from spreading to more people.