Medical Signs - Signs Versus Symptoms

Signs Versus Symptoms

Signs are different from symptoms, the subjective experiences, such as fatigue, that patients might report to their examining physician.

For convenience, signs are commonly distinguished from symptoms as follows: Both are something abnormal, relevant to a potential medical condition, but a symptom is experienced and reported by the patient, while a sign is discovered by the physician during examination or by a clinical scientist by means of an in vitro examination of the patient.

A slightly different definition views signs as any indication of a medical condition that can be objectively observed (i.e., by someone other than the patient), whereas a symptom is merely any manifestation of a condition that is apparent to the patient (i.e., something consciously affecting the patient). From this definition, it can be said that an asymptomatic patient is uninhibited by disease. However, a doctor may discover the sign hypertension in an asymptomatic patient, who does not experience "dis-ease", and the sign indicates a disease state that poses a hazard to the patient. With this set of definitions, there is some overlap – certain things may qualify as both a sign and a symptom (e.g., a bloody nose).

Lester S. King, author of Medical Thinking, argues that an "essential feature" of a sign is that there is both a sign and a "thing signified". And, because "the essence of a sign is to convey information", it can only be a sign, properly speaking, if it has meaning. Therefore, "a sign ceases to be a sign when you cannot read it". A person, who has and exercises the knowledge required to understand the significance or indication or meaning of the sign, is necessary for something to be a complete sign. A physical phenomenon that is not actually interpreted as a sign pointing to something else is, in medicine, merely a symptom. Thus, King rejects "these present-day views, however widely accepted, as quite faulty, at variance not only with ordinary usage but with the entire history of medicine."