I'm getting a lot of purple spider blood veins on my legs. is it caused by liver disease?

If they're only on your legs,I wouldn't attribute them to advanced liver disease. The ones on the legs are actually related to capillary, venule and arteriole weakness & damage, are located just below the skin,are harmless but may have associated varicose veins & tend to run in families. Dermatologists and vascular surgeons treat them with injections or laser.