Bulging veins aren’t always a sign of danger, but they can sometimes indicate an underlying medical issue. Understanding why veins become more visible is important for recognizing potential health concerns.

Common causes include excessive exercise, aging, hot temperatures, tight clothing, genetics, sun exposure, and being overweight. In some cases, bulging veins may be harmless, but if they appear with discoloration, it’s best to consult a healthcare provider.

Veins bulge when blood pools in weakened or damaged veins, rather than flowing smoothly back to the heart. This often results in varicose veins—swollen, twisted veins that typically appear on the legs but can also show up on the arms.

According to Cleveland Clinic, varicose veins are often triggered by hormonal changes (especially during pregnancy), obesity, genetics, smoking, or spending long periods standing or sitting.

Doctors may recommend treatments such as compression stockings, leg elevation, injection therapy, or even vein surgery, depending on severity.

If untreated, varicose veins may lead to venous ulcers, which are open wounds that form near the ankles and heal slowly due to poor circulation.

Other serious complications include blood clots, which can develop into conditions like deep vein thrombosis, superficial thrombophlebitis, or pulmonary embolism.

While varicose veins can’t always be prevented, you can reduce your risk by staying active, losing weight, quitting smoking, and wearing loose clothing, especially around the waist.