One morning, you glance down at your hands while reaching for your coffee and notice something that makes you pause. There, beneath your skin, a network of blue-green lines seems more prominent than you remember. Or perhaps you’re getting dressed and catch sight of veins on your legs that appear more pronounced than before. These moments of discovery can range from mildly curious to genuinely concerning, depending on the circumstances surrounding their appearance. While our vascular system is always present beneath the surface, working tirelessly to circulate blood throughout our bodies, there are times when it becomes more visible—and understanding when this visibility signals something important can be crucial for maintaining optimal health.