Varicose veins can occur at any time, especially in those who have a family history of varicose veins and venous reflux disease, also known as venous insufficiency. When a male member of the family has venous insufficiency, almost all of the kids will develop varicose veins at some time or another. If we live long enough, all of us will develop varicose veins, reticular veins and spider veins. It is inevitable, as all veins have valves and vein valves degenerate over time ..... this is a vicious cycle, as more vein valves leak, veins get larger and more vein valves become insufficienct. In essence, your best bet is to walk every day, elevate your legs when you are sitting down (recliner), wear compression stockings and take something called horse chestnut extract (aescin) or a bioflavonoid formula. I have written books about horse chestnut extract and bioflavonoids for vein problems and I highly recommend it to all of my patients (except those with liver problems, those who are pregnant and those who are breast feeding).
I also recommend that you get tested by a phlebologist (vein specialist) with a Doppler venous scan to see if you have venous insufficiency. If you do, this problem has to be treated with VNUS Closure or EVLT. After that, you need to have your varicose veins (bulging veins) and spider and reticular veins treated with sclerotherapy (preferably foam sclerotherapy) by an expert in the field. You can go to the major phlebology website and find a Board Certified Phlebologist to help guide you through this process.
In regards to moving to a warmer climate, I can say that veins become more dilated and more apparent in warmer temperatures and perhaps this is why you are noticing more of them ... or the fact that you are on birth control is making them proliferate more. Again, you need to be evaluated by a vein specialist and have the existing problems (venous reflux) and varicose veins treated before they proliferate more - which would require more extensive treatments and complications over time (skin discoloration with hyperpigmentation).