Symptoms. The main symptom of varicose veins is a patch of raised, twisted veins that can easily be seen on the surface of the skin. At first, the veins will be unsightly, but they will cause no other symptoms. However, if a blood clot develops in them, the patch of veins may become painful, swollen, and red. The leg that has the varicose veins may start to ache constantly too, especially if a person has a sedentary lifestyle.