外科学, or "surgery," is a branch of medicine that focuses on diagnosing and treating diseases and injuries through operative procedures. Surgeons perform various types of surgeries, which can range from minor outpatient procedures to complex operations requiring hospitalization. The field of 外科学 encompasses various specialties, including 心脏外科 (cardiac surgery), 神经外科 (neurosurgery), and 整形外科 (plastic surgery). Each specialty addresses specific medical conditions, utilizing advanced techniques and technologies to improve patient outcomes and enhance quality of life.