How likely is it that I have ms? What is the prevalence of MS in the u.S.?

MS in USA PREVALENCE. Estimates are 85 cases per 100000 people thats it so you can guess your odds.
This varies. The exact number of cases in the usa may be 400, 000, and worldwide, 2.5 million, but I think it is far higher. Have seen incidence figures in various states, over the past 5 yrs, go from 1in 800 to 1 in 540. Obviously depends how far north you live and grow up, as incidence increases north of latitude 42. If you worry about ms, talk to your family doc first.