Veins popping out simply mean visible veins. This is a condition wherein the outline of veins is seen on the surface of skin and gives a slightly greenish hue to that part of the skin. Many people consider veins popping out of arms, especially in the region of the biceps and triceps to be a very desirable quality. Some people also believe that veins popping out is a sign of being thin, or fit and lean. Thus, it is quite a desirable trait for a good chunk of the population. However, some people are also wary of this. So what does visibility of veins through the surface of skin signify? Given below is the answer to this elusive question... Why do Veins Pop Out? There are many reasons for popping out of veins in the body. Basically, there are two important factors that contribute towards popping out of veins. The first is genetics. Genetics plays an important role in determining whether or not there will be popping out of veins visible on the surface of skin. The other factor is having a low body fat percentage and high muscle mass. Lowering body fat greatly helps in leading to veins popping out of legs and arms. By dieting, lowering the amount of body fat and following a high protein diet, the chances of developing arms and legs that have veins popping out is higher. Do Veins Pop Out After Workout? Many people think that veins are especially seen to pop out after rigorous workouts. Hence, it is believed that when a person does any kind of rigorous exercise, the veins tend to get filled up and so are visible through the skin. This is, however, a misconception. When a person exercises, or does any other physically demanding activity, the heart rate and strength of contraction of heart muscles increase and blood is quickly pumped into the arteries. The venous volume and pressure thereby, actually decreases and so, filling up of veins with blood is not the basis for veins popping out. On the contrary, the process that occurs in the capillaries as a result of a rise in the arterial blood pressure during exercise causes the plasma fluid, which is otherwise resting in small tributaries, to be forced out through the thin vessel walls and into compartments surrounding the muscles. This process, which is known as filtration, leads to swelling and hardening of the muscles, which is quite noticeable during exercise. As a result of this swelling, the cutaneous veins, that is, veins that are present in the skin and closer to the surface of skin are pushed further towards the skin surface. They thus, flatten to some extent, and appear to bulge out. Such veins are more visible in people who obviously have less subcutaneous fat and more of lean muscle mass. It is also a myth that popping of veins during exercising is a sign of overexertion of muscles and hence, exercising should be stopped at this stage. However, as explained above, this popping of veins is neither good nor bad, but simply a result of normal physiological mechanisms that occurs as a result of rise in arterial blood pressure during any kind of physical exertion. This was all about how veins pop out and what it actually means. Though many people find it a desirable trait, it may not always be a sign of attractiveness. Veins popping out of hands is also considered to be a sign of aging, because as a person ages, the skin of the hand becomes loose and the veins of the hand then become more visible on the surface of the skin. Hence, it is best to try to concentrate on keeping the body fat content under control and stay healthy rather than concentrating on getting your blood vessels to come closer to the surface of your skin!