Patients report what they feel; clinicians interpret what it means. A symptom is a subjective experience of disease or injury reported by the patient, such as pain, fatigue, nausea, or dizziness.

Symptoms differ from signs, which are objective findings observed by the examiner. The same symptom can arise from many causes, so history explores onset, duration, quality, severity, triggers, and associated features. Symptom patterns often point toward specific diagnoses before tests are ordered.

Some symptoms are sensitive but not specific; others are highly suggestive of particular diseases. Addressing symptom relief alongside diagnostic work-up is part of compassionate care. Patient-reported symptom scales are increasingly used to monitor treatment response and quality of life.

• Subjective experience of illness reported by the patient
• Distinct from objective clinical signs
• Characterized by onset, quality, and associated features
• Guides differential diagnosis and symptomatic treatment