Stress
A lot of the stress you'll find in the upholstery field is in the springs and straps inside the furniture. Of course, you may encounter financial stress if you work for yourself and business is slow. Or if you are paid by the piece and happen to be a very slow worker.
But for the most part, this is a pretty relaxing job. Some might even call it therapeutic. Your main activities reside in the realm of "arts and crafts," such as needlepoint or woodworking.
Throw in a little dose of creativity in picking the right fabric, and you've got a job that lets you go into your happy place while your hands work purely from muscle memory. It's difficult to stay worried or stressed about anything when your attention is focused on the details at hand.