People with lower body fat or more developed muscles may have especially noticeable veins because the veins sit closer to the skin. Lighter or thinner skin can also make them appear more prominent.
Heat and exercise can temporarily make veins stand out more as blood vessels expand to help regulate body temperature and increase blood flow. In most cases, this is completely normal.
However, veins that suddenly become painful, swollen, discolored, or noticeably different may need medical attention. Changes like these can sometimes point to an underlying problem and should not be ignored.
