A symptom is subjective from the patient point of view. A symptom is what the patient experiences about the illness, injury or disease. Symptoms can only be experienced, they are not able to be observed or measured objectively. Pain is a symptom. I do not know you are having pain unless you tell me. Nausea is also a symptom, as are: chills, numbness, fatigue, vertigo, malaise, itching, stomach cramps, burning on urination, etc. Symptoms can be characterized by the patient to help the physician diagnose the problem with that added information to consider along with the observations, measurements, laboratory findings and other diagnostic test results that are the objective signs.
A sign is an objective physical manifestation of illness, injury or disease. It is an objective finding, something one can observe and measure. A rapid pulse, a high temperature, a low blood pressure, an open wound, bruising, etc. are all signs. Signs give a more definite indication of the presence of a particular disease to the physician. Signs may be described as the current 'showcase' that the doctor observes in the patient and in the diagnostic testing and measurements.
So in the simplest form, signs are observations of the doctor and symptoms are the experiences of the patient.
