Diazepam, commonly known by the brand name Valium, is a benzodiazepine medication primarily used to treat anxiety disorders, muscle spasms, seizures, and alcohol withdrawal symptoms. It acts on the central nervous system by enhancing the effects of gamma-aminobutyric acid (GABA), a neurotransmitter that inhibits brain activity, thereby inducing a calming effect. Diazepam is also used as a sedative before medical procedures.