When you find yourself asking, why are my veins so visible, there’re factors other than the age to consider of. For example, the thinning of layer of the skin that brings about the prominent of the veins in the first place can be brought about by various activities or sometimes illness. It could be that you are drinking less water, or that the weather is getting colder, maybe you are getting more stress about work. For women, visible veins along the breast could mean an oncoming period or a new addition to the family. Weight loss and strength training too would often make the vein more visible, being athletic would mean less fat and less of the tissue layer. It shouldn’t be a cause of concern, it’s just your body dealing with your lifestyle changes. Do visit a doctor however if you are feeling ill.