If you are like many other people, you may have noticed a few varicose veins or spider veins on your legs, but you don't worry about them. After all, they're common – 27% of the adult population has them, right? And they're not serious…just a cosmetic issue, right? Wrong. These unsightly, bulging veins are symptoms of a disorder that afflicts more than 26 million Americans – vein disease. And it's more serious than you think.