Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS) that typically appears in late adolescence or early adulthood. Early symptoms include numbness, double vision, paresis, bladder control problems, ataxia, and tremor. Treatment is based on the progression of the disease and symptoms, including fatigue, spasticity, urinary dysfunction, emotional problems, cognitive dysfunction, and pain. MS is an immune-mediated disease, acquired by a genetically predisposed person near the time of puberty. Epidemiologic and pathologic aspects, as well as a host of immunologic factors, must be taken into account when considering the mechanism of demyelination. The areas most commonly affected by MS include motor, sensory, cerebellar, and emotional areas. Sexual dysfunction can affect the quality of life in MS patients, who are usually of childbearing age. For the MS patient, rehabilitation should become a way of life, not an on/off modality.