Abstract: An online medical evaluation and treatment system includes a patient interface, a physician interface and diagnostic tools to gather and sort information sent from the patient and automatically generate candidate diagnoses. A patient enters information about a medical condition through the patient interface. The diagnostic tools evaluate the information provided by the patient, generate further questions, and create a list of possible diagnoses known as a differential diagnosis. A physician enters the physician interface to review a patient file and diagnose the medical condition of the patient. Importantly, the physician does not have to be present as the data is gathered from the patient, thus saving the physician time. The information gathered from the patient may also be exported to external databases for processing by a third party.