Symptoms

Symptoms are subjective experiences reported by a patient that indicate an abnormal function or disease. They are distinct from signs, which are objective findings observed by others or found on examination or testing. Common symptoms include pain, fatigue, fever, nausea, dizziness, shortness of breath, cough, rash, and mood changes. Symptoms can be acute or chronic, and may be intermittent or persistent, varying in intensity.

In clinical practice, symptoms guide history-taking and form the basis of the differential diagnosis. Clinicians document characteristics such as onset, duration, location, quality or character, intensity, provoking or relieving factors, timing, and associated symptoms. These details help distinguish among possible causes and direct further workup.

Measuring symptoms often relies on patient reports, using tools such as visual analog scales for pain or standardized questionnaires for fatigue, sleep disturbance, or mood. Because symptoms are subjective, they are interpreted in conjunction with objective signs and test results.

Variability in symptom reporting can arise from cultural, linguistic, and psychological factors, and some individuals may under- or over-report symptoms. Red flag symptoms require urgent evaluation, such as chest pain with radiation, sudden severe headache, confusion or weakness, or rapidly worsening shortness of breath.

Understanding symptoms is central to medical assessment and management. They guide history, help generate hypotheses, and inform decisions about testing and treatment, while not by themselves proving a diagnosis.