Diagnosis

Diagnosis (from the Greek 'dia' — through + 'gnosis' — knowledge) is the process by which a clinician identifies the nature of a patient's illness. It is the foundation of all medical care — accurate diagnosis directs appropriate treatment, appropriate referral, and accurate prognosis. Misdiagnosis or delayed diagnosis can have serious consequences — from delayed cancer treatment to inappropriate management of serious conditions.

The diagnostic process involves: clinical history (what symptoms, when they started, associated factors, past medical history, medications, family history — often the most important component); physical examination (vital signs, systemic examination of relevant organ systems); and investigations (blood tests, imaging, pathology, microbiology, and specialist tests) to confirm or exclude diagnoses. The physician generates a 'differential diagnosis' — a ranked list of possible diagnoses consistent with the clinical picture — and then uses investigations to discriminate between them.

In Korea, GPs at local clinics have access to a broad range of near-patient investigations (blood tests, urine tests, ECG, spirometry) enabling diagnosis of most common conditions in primary care. Major hospitals provide specialist diagnostic services including advanced imaging, endoscopy, pathology, and genetics. The increasing use of artificial intelligence (AI) in radiology and pathology at Korea's hospitals is improving diagnostic speed and accuracy — Korea is a global leader in AI-assisted medical imaging research. Patients have the right to seek a second opinion — particularly for serious or uncertain diagnoses.