Girls hand blue veins suddenly very obvious and body type is thin, heavy physical labor and exercise, the surrounding environment, high temperature and other physiological or natural factors, may also be related to atherosclerosis and other pathological factors. Green tendon is mainly refers to the human body surface abnormally exposed green tendons, that is, blood vessels. 1. Thin and weak people: the obvious blue veins indicate that there is less fat under the skin, and the reduction of the fat layer can cover the blood vessels on the surface of the body, which is common in the thin people. 2. Heavy laborers and athletes: Generally, the blood vessels on the hands of women who do heavy labor and sports are relatively obvious, and the skin color is lighter, which makes the veins stand out more easily. 3. High-temperature environment: If the temperature of the surrounding environment suddenly rises, the blood vessels will also appear obvious expansion, and look obvious veins. 4. Atherosclerosis: When the blood flow of atherosclerosis patients is not smooth, obvious veins can also appear. If accompanied by blood clots, may appear hand edema, should be vigilant. Most of the hands suddenly very obvious veins belong to the normal phenomenon, but there may be other reasons, it is recommended to go to the hospital, diagnosis and give a clear targeted treatment or treatment.