One of the difficult things with MS is that symptoms like numbness can happen randomly all the time to different people and not represent MS. The main feature that should bring someone's attention to consider seeing a doctor is if there's new onset numbness that lasts a day, a week, or two weeks and it tends to travel. Like the arm, the leg, the face. It will start in one place and progress. That would be one of the ways you can distinguish MS from crossing your legs and getting some numbness because you're compressing a nerve transiently.
