Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system, including the brain and spinal cord. In MS, the immune system mistakenly attacks the protective myelin sheath that surrounds nerve fibers, disrupting the transmission of electrical signals between the brain and the rest of the body. This damage can lead to a wide range of symptoms, such as muscle weakness, numbness or tingling, vision problems, balance and coordination difficulties, fatigue, and cognitive changes. The course of the disease varies, with some individuals experiencing periods of relapse and remission, while others have gradual progression. The exact cause is not fully understood but involves a combination of genetic susceptibility and environmental factors.