Symptom

A symptom (from Greek σύμπτωμα, "accident, misfortune, that which befalls", from συμπίπτω, "I befall", from συν- "together, with" + πίπτω, "I fall") is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality. A symptom is subjective, observed by the patient, and cannot be measured directly.

The term is sometimes also applied to physiological states outside the context of disease, as for example when referring to "symptoms of pregnancy".