When we visit a doctor with a health problem they check your pulse, Blood pressure and sometimes ask you to get scanned. They sometime recommend urine, blood and other tests in order to diagnose what disease you are affected with.
GE with help from MIT SENSEable City Lab came up with a interactive map to show how symptoms are all connected so that it becomes easy at looking at a picture to arrive at the correct diagnosis.
This info graphic developed by GE and MIT are based on 7.2 million medical records gathered between 2005 to 2010. Using these data MIT students where able to identify how one symptom is linked to another symptom (symptoms of cough will follow with fever and body pains etc). Here is a cool graph of how all the symptoms are connected. The color coding has some significance too and related diseases are connected with similar color codes.
Link to the info graphs http://visualization.geblogs.com/visualization/network/