A hospital is a type of medical facility that provides around-the-clock health care to patients with severe or complex illness or injury. It is generally staffed by doctors, nurses, and other healthcare professionals. The hospital may be equipped with various medical facilities including operating rooms, intensive care units, labs, and imaging equipment. The hospital is designed to diagnose and treat disease and injury in a systematic and coordinated manner. It is distinguished from clinics, which are usually smaller, provide more routine health care services, and do not admit patients overnight.

Hospitals have a long history in human society and were originally “places of hospitality” where sick pilgrims would be cared for. Religions often recognized certain deities as healers and early hospitals were built at the temples of these gods. The Roman emperor Constantine converted the pagan hospitals to Christian care and the concept of the hospital as it exists today emerged from this.

The most common type of hospital is a general hospital that deals with many kinds of illness and injury and has a large number of beds for inpatients. These have a major accident and emergency department to deal with serious and life-threatening injuries, and a range of acute departments such as surgery, medicine, and physiotherapy.

Other types of hospital include specialty hospitals that focus on particular medical conditions such as heart, eye, or kidney disease. There are also hospitals that cater to specific groups such as children or seniors. In addition, there are hospitals that combine a range of specialties under one roof (e.g., the Mayo Clinic).