From DMJ Productions
Surgeons at Work

Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (i.e., malabsorption created by bariatric surgery such as gastric bypass), to reconstruct or improve aesthetics and appearance (cosmetic surgery), or to remove unwanted tissues (body fat, glands, scars or skin tags) or foreign bodies. The subject receiving the surgery is typically a person (i.e. a patient), but can also be a non-human animal (i.e. veterinary surgery).

The act of performing surgery may be called a surgical procedure or surgical operation, or simply "surgery" or "operation".

From Wikipedia