I want to learn about varicose vein prevention methods.

I often worry about my legs swelling frequently, and I think it's because blood circulation isn't good. So I looked into varicose veins, but there are many different pieces of information, so I wasn't sure which one is correct. I've seen legs with varicose veins before, and I thought it looked really bad because of the bulging tendons. I want to know how to prevent varicose veins from developing. Also, I'm curious about how the symptoms appear in the early stages. If you get varicose veins, does it hurt a lot? I wonder if the only treatment method is a procedure.