One of the reasons why a doctor would want to keep track of a patient's vital signs over an extended amount of time is because doing so can allow a medical professional to offer a more informed opinion on why particular symptoms might be occurring or what disease those symptoms might signify. Patient monitors may be handled by machinery that can track for a significant amount of time or may be able to electronically communicate specific stats through delivery to a mobile or smart phone which can allow for a very fast delivery of information to the doctor.