医院是治疗和护理病人的机构，也兼做健康检查、疾病预防等。在日语跟**等也称为病院。是由专业分工的医院职员通过医学检查、检验、治疗等设备提供医疗及患病休养服务的一种医疗机构，其服务对象为觉察或认可自己心理上或生理上有严重问题的疾病患者、伤者和接受分娩的孕妇，或者是受到家人和朋友极力劝导到医院寻求帮助的来访者，或者是需要常规健康管理的一般人士。虽然也有同普通诊所类似的门诊服务，但最大的区别在于医院的留院治疗资源、规模、模式。

大部分医院通常是由政府部门资助，或由宗教团体、社会组织、公司或慈善机构的慈善捐款，不以盈利为目的。同时，也存在以盈利为目的的私立医院。

A hospital is a health care institution providing patient treatment with specialized staff and equipment. The best-known type of hospital is the general hospital, which has an emergency department. A district hospital typically is the major health care facility in its region, with large numbers of beds for intensive care and long-term care. Specialised hospitals include trauma centres, rehabilitation hospitals, children's hospitals, seniors' (geriatric) hospitals, and hospitals for dealing with specific medical needs such as psychiatric problems (see psychiatric hospital) and certain disease categories. Specialised hospitals can help reduce health care costs compared to general hospitals.