Plastic surgery is a surgical specialty involving the restoration, reconstruction, or alteration of the human body. It can be divided into two main categories: reconstructive surgery and cosmetic surgery. Reconstructive surgery includes craniofacial surgery, hand surgery, microsurgery, and the treatment of burns. While reconstructive surgery aims to reconstruct a part of the body or improve its functioning, cosmetic (or aesthetic) surgery aims at improving the appearance of it.

Reconstructive plastic surgery is performed to correct functional impairments caused by burns; traumatic injuries, such as facial bone fractures and breaks; congenital abnormalities, such as cleft palates or cleft lips; developmental abnormalities; infection and disease; and cancer or tumors. The goal of reconstructive plastic surgery is to restore both form and function.

The most common reconstructive procedures are tumor removal, laceration repair, maxillofacial surgery, scar revision, hand surgery and breast reduction plasty. According to the American Society of Plastic Surgeons, the number of reconstructive breast reductions for women decreased in 2018 by 4 percent from the year before. Breast reduction in men decreased in 2018 by 8 percent. In 2018, there were 57,535 performed.

Some other common reconstructive surgical procedures include breast reconstruction after a mastectomy for the treatment of cancer, cleft lip and palate surgery, contracture surgery for burn survivors, and creating a new outer ear when one is congenitally absent.

Plastic surgeons use microsurgery to transfer tissue for coverage of a defect when no local tissue is available. Free flaps of skin, muscle, bone, fat, or a combination may be removed from the body, moved to another site on the body, and reconnected to a blood supply by suturing arteries and veins as small as 1 to 2 millimeters in diameter.