Surgery is an ancient medical specialty

Medicine

Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

 that uses operative manual and instrumental techniques on a patient

Patient

A patient is any recipient of healthcare services. The patient is most often ill or injured and in need of treatment by a physician, advanced practice registered nurse, veterinarian, or other health care provider....

 to investigate and/or treat a pathological condition such as disease

Disease

A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

 or injury

Injury

-By cause:*Traumatic injury, a body wound or shock produced by sudden physical injury, as from violence or accident*Other injuries from external physical causes, such as radiation injury, burn injury or frostbite*Injury from infection...

, or to help improve bodily function or appearance.

An act of performing surgery may be called a surgical procedure, operation, or simply surgery. In this context, the verb operate means to perform surgery.