The Symptom reference article from the English Wikipedia on 24-Apr-2004
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Symptom

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A symptom is a sensation or change in health function experienced by a patient. It is a subjective report, as opposed to a sign, which is objective evidence of the presence of a disease or disorder.

Examples of symptoms are fatigue/tiredness, heat intolerance, or nausea. In contrast, elevated blood pressure, or abnormal appearance of the retina, are signs of disease.