Multiple sclerosis (MS) is a disease that affects your brain and spinal cord. MS occurs when the immune system attacks the fatty substance called myelin that coats the nerves. This attack leads to inflammation and the breakdown of myelin, causing communication problems between your brain and the rest of your body.

"The area the inflammation affects in the brain and spinal cord will determine the type of symptoms a person develops," says Elena Grebenciucova, MD, a specialist in multiple sclerosis and neuroimmunology at Northwestern Medicine. "People can develop various symptoms depending on the area of the brain or spinal cord affected, and those symptoms are different for everyone."  

The cause of MS is unknown, and the course of the disease in a given person is unpredictable. However, research suggests that certain factors increase your risk for developing MS:

Here's a closer look at some of the common symptoms of MS.