A hospital is a health care institution providing patient treatment with specialized medical and nursing staff and medical equipment. The best-known type of hospital is the general hospital, which typically has an emergency department to treat urgent health problems ranging from fire and accident victims to a heart attack. A district hospital typically is the major health care facility in its region, with large numbers of beds for intensive care and additional beds for patients who need 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 treatment (see psychiatric hospital) and certain disease categories. Specialised hospitals can help reduce health care costs compared to general hospitals.
A teaching hospital combines assistance to people with teaching to medical students and nurses. The medical facility smaller than a hospital is generally called a clinic. Hospitals have a range of departments (e.g. surgery and urgent care) and specialist units such as cardiology. Some hospitals have outpatient departments and some have chronic treatment units. Common support units include a pharmacy, pathology, and radiology.
Hospitals are usually funded by the public sector, health organisations (for profit or nonprofit), health insurance companies, or charities, including direct charitable donations. Historically, hospitals were often founded and funded by religious orders, or by charitable individuals and leaders.
Currently, hospitals are largely staffed by professional physicians, surgeons, nurses, and allied health practitioners, whereas in the past, this work was usually performed by the members of founding religious orders or by volunteers. However, there are various Catholic religious orders, such as the Alexians and the Bon Secours Sisters that still focus on hospital ministry in the late 1990s, as well as several other Christian denominations, including the Methodists and Lutherans, which run hospitals. In accordance with the original meaning of the word, hospitals were originally "places of hospitality", and this meaning is still preserved in the names of some institutions such as the Royal Hospital Chelsea, established in 1681 as a retirement and nursing home for veteran soldiers.
During the Middle Ages, hospitals served different functions from modern institutions. Middle Ages hospitals were almshouses for the poor, hostels for pilgrims, or hospital schools. The word "hospital" comes from the Latin hospes, signifying a stranger or foreigner, hence a guest. Another noun derived from this, hospitium came to signify hospitality, that is the relation between guest and shelterer, hospitality, friendliness, and hospitable reception. By metonymy the Latin word then came to mean a guest-chamber, guest's lodging, an inn. Hospes is thus the root for the English words host (where the p was dropped for convenience of pronunciation) hospitality, hospice, hostel and hotel. The latter modern word derives from Latin via the ancient French romance word hostel, which developed a silent s, which letter was eventually removed from the word, the loss of which is signified by a circumflex in the modern French word hôtel. The German word 'Spital' shares similar roots.
The grammar of the word differs slightly depending on the dialect. In the United States, hospital usually requires an article; in the United Kingdom and elsewhere, the word normally is used without an article when it is the object of a preposition and when referring to a patient ("in/to the hospital" vs. "in/to hospital"); in Canada, both uses are found.
Some patients go to a hospital just for diagnosis, treatment, or therapy and then leave ("outpatients") without staying overnight; while others are "admitted" and stay overnight or for several days or weeks or months ("inpatients"). Hospitals usually are distinguished from other types of medical facilities by their ability to admit and care for inpatients whilst the others, which are smaller, are often described as clinics.