Have you noticed your veins suddenly becoming more visible? For many, it’s harmless, but experts warn that sometimes it signals “underlying circulatory problems that shouldn’t be ignored.”

Veins return blood to the heart and are easily affected by factors like age, genetics, and temperature. Common, harmless causes include low body fat, aging skin, and exercise, which “causes veins to expand.” Heat can make veins dilate, and for some, visibility is simply genetic.

However, visible veins can also point to health issues. Chronic Venous Insufficiency occurs when vein valves weaken, causing “swelling, heaviness, and bulging veins.” Varicose veins appear twisted and painful, while Superficial Thrombophlebitis involves a clot near the surface that feels firm and tender. The most serious, Deep Vein Thrombosis, causes sudden swelling, pain, and redness—and “is a medical emergency.”

Temporary triggers like dehydration, intense workouts, or hormonal changes can also make veins stand out. But if you notice pain, warmth, or skin discoloration, “consult a healthcare provider.”

Treatment options include lifestyle changes, compression stockings, or medical procedures. In most cases, visible veins are harmless—but they’re also “a window into your body’s circulatory health.”