Varicose veins for years

I have varicose veins for years and was wondering if it was serious and should go to any nearby clinic like the Vaughan vein clinic in Toronto, where we live.The vein goes over my right knee as well as it is painful some days to walk. While browsing I found that varicose vein treatments are effective, but it may have some side effects. Has anyone done this treatment recently? Any doctor you know of and can recommend. How much would the treatment cost and how long could it go?