Have you noticed some dark veins on your legs, arms, or face that you hadn't noticed before? It's not uncommon to be able to see blue veins deep under the skin, but perhaps, your veins have become raised and darker in color. Over time you may have also noticed some other symptoms like heaviness or swelling in your legs or pain around the veins. While these symptoms may just be aesthetically unappealing or uncomfortable, they can also point to underlying health conditions that need to be treated. Let's take a look at what regular changes or factors cause dark veins, and when it's time to be concerned.