- An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.
Definition from: Physician Data Query via Unified Medical Language System at the National Library of Medicine
- Subjective evidence of disease or physical disturbance observed by the patient <headache is a symptom of many diseases> <visual disturbances may be a symptom of retinal arteriosclerosis>; broadly: something that indicates the presence of a physical disorder.
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
Related discussion in the Handbook
See also Understanding Medical Terminology.