Many illnesses do not require admission to a hospital and can be treated without admission to a hospital. Many investigations can be performed on an ambulatory basis, including blood tests, X-rays, endoscopy , etc.

• Ambulatory care and outpatient care as terms are being used interchangeably.
• Ambulatory care is any health care delivered on an outpatient basis. Health care including diagnosis, observation, treatment and rehabilitation. Health care treatment provided to a patient who is not confined in a health care facility.
• If the patient makes the trip to the doctor's office or surgical center without an overnight stay, it is considered ambulatory care.
• Outpatient care includes services that do not require an overnight stay, such as emergency treatment, same-day surgery, outpatient diagnostic tests, and physician office visits.
• Many surgeries and treatments are now provided on an outpatient basis, while previously they had been considered reason for inpatient hospitalization.
• It is been argued that outpatient care is the fastest growing segment of healthcare in the US.