Neurological disorders are a group of disorders that involve the central nervous system (brain, brainstem and cerebellum), the peripheral nervous system (including cranial nerves), and the autonomic nervous system (parts of which are located in both central and peripheral nervous system). Major branches are headache, stupor and coma, dementia, seizure, sleep disorders, trauma, infections, neoplasms, neuroophthalmology, movement disorders, demyelinating diseases, spinal cord disorders, and disorders of peripheral nerves, muscle and neuromuscular junctions.

Many mental illnesses are believed to be neurological disorders of the central nervous system, but they are classified separately. They are not traditionally listed as neurological diseases because their causes are not definitely determined as biological, although there are good reasons to suspect that bipolar disorder and schizophrenia have neuro-chemical causes.

See also: List of neurological disorders