Ever noticed bright blue veins on the backs of your hands and wondered if it’s normal? You’re not alone, and the answer is a bit nuanced. These veins are part of a network of superficial veins just beneath the skin. For many people, they’re simply “a completely normal feature of your anatomy,” especially if you have fair or thin skin, or as you age and your skin naturally thins.

Veins can also appear more prominent after exercise. If you’re lean or active, you may see them “pop” after a good workout because muscle activity pushes veins closer to the skin. Pregnant women and athletes often notice this due to increased blood flow and pressure in the circulatory system.

However, visible veins aren’t always harmless. Bulging or blue veins can be an early sign of varicose veins, which “occur when veins become stretched and weakened, causing them to twist and enlarge.” On the hands, they may look like thick, rope-like lines. While often harmless, they can sometimes cause discomfort or signal underlying issues.

Pay attention if veins start to ache, feel warm, or appear red and swollen, as these may indicate a blood clot or serious vascular problems, like deep vein thrombosis (DVT) or pulmonary embolism — both potentially life-threatening if untreated.

To keep veins healthy, stay active, maintain a healthy weight, take breaks from long periods of sitting or standing, avoid tight clothing, and quit smoking. If varicose veins or pain concern you, options range from lifestyle changes to treatments like compression therapy, sclerotherapy, or vein surgery. The Cleveland Clinic notes that about one in three adults deal with varicose veins, and “most of the time, it’s nothing to worry about.” But if they start to bulge, throb, or hurt, don’t ignore it — sometimes “your veins might just be” giving subtle clues before bigger issues arise.