Neurosurgery is the discipline in medicine that focuses on the diagnosis and treatment of the central, peripheral, and autonomic nervous system. Because of this emphasis, it is a discipline that focuses on a complete system rather than any specific region of the body. It is first and foremost a surgical discipline, and with rare exception, its practitioners are physicians who operate on the nervous system.

Because the nervous system encompasses all parts of the body, a neurosurgeon may operate on the brain, spine, or extremities in a given day or week. Neurosurgeons operate on patients of all ages, treating abnormalities that range from congenital anomalies of the newborn, to trauma, to tumors, to vascular anomalies or infections of the brain or spine, to abnormalities of the aging such as stroke or degenerative diseases of the spine. Like the neurologist, the neurosurgeon is an expert in the diagnosis of neurologic disorders, capable of interpreting a variety of radiological studies such as CT scans, magnetic resonance images, and angiograms. Unlike the neurologist, the neurosurgeon focuses on surgical approaches in the treatment of patients.

Neurosurgery is among the youngest of surgical disciplines, dating back to the early 1900s. The early greats in neurosurgery were well-trained general surgeons who specialized in the nervous system. Many were also creative scientists who used their expertise in neurophysiology to become expert clinicians. Because it is a young specialty, neurosurgery is rapidly evolving. An important tradition in neurosurgery is change and rapid dissemination of new ideas and techniques. Today neurosurgeons practice in a variety of locations from academic centers, to community hospitals, to major research facilities such as the NIH. After adequate training, a practitioner of the art of neurosurgery has many opportunities for a variety of career paths. Successful practitioners of this young specialty embrace change and recognize that during their careers they will continue to change and grow, incorporating new techniques and ideas in the treatment of their patients.

The community of neurosurgeons is relatively small. In the United States there are about 3,500 Board-certified neurosurgeons, and there are only 95 approved training programs in the United States and Canada. Each year there are approximately 140 new training positions open and 130 residents who graduate. The total number of residents in the United States is about 725. Subspecialization has become a part of neurosurgery, and there are now post-residency graduate training positions or fellowships in pediatric neurosurgery, spine surgery, interventional neuroradiology, vascular surgery, neuro-oncology, pain, trauma, and functional and stereotactic neurosurgery.