What is multiple sclerosis? Multiple sclerosis is a progressive autoimmune disease and the most common neurological disease diagnosed in young adults. It is believed that multiple sclerosis occurs when the body’s own immune system attacks the central nervous system. Commonly called MS, the disease generally gets worse with time and can cause significant nerve damage. The progression and severity of multiple sclerosis varies greatly among individuals. The severity of multiple sclerosis ranges from mild to severe and disabling, and it can result in muscle weakness, loss of balance, and difficulty walking. In some cases, multiple sclerosis can lead to serious complications, such as choking and paralysis. Early diagnosis and medical care can help manage and control symptoms and minimize complications of multiple sclerosis.