How many MS patients are there in the US?

400,000.

According to the National Multiple Sclerosis Society, there are about 400,000 MS patients in the US, and this number is constantly growing: about 200 people are diagnosed each week. Multiple sclerosis is an autoimmune disease that affects between 2 and 3 times more women than men; MS diagnosis usually occurs in the age range of 20-50 years.