Diagnosis is a fundamental aspect of medicine and healthcare, involving the identification and determination of the nature and cause of a patient's illness or condition. It is the process of analyzing a patient's symptoms, medical history, and test results to reach a conclusion regarding the underlying disease or condition. Diagnostic techniques can range from physical exams and medical history assessments to laboratory tests, imaging studies, and biopsies. The goal of diagnosis is to guide appropriate treatment and management strategies for the patient, ultimately leading to improved health outcomes.