Well, I haven't heard of CO for varicose veins. But if you have varicose veins, you need to see a doctor and have them checked. The doctor might advise you to take sclerotherapy or laser treatment. Don't take any chances, see a doctor. Here's a link which I found with lists of doctors for varicose veins, http://doctorfinders.com/varicosevein.php.
Good luck!