The intravenous valve prevents the blood coming from the lower side from coming back down.
However, if this valve breaks, the blood that comes back and the blood that comes up will swirl.
The pressure causes the veins to bloat.
It is not visible when lying down.
However, if you stand, the blood pressure of your blood vessels will rise because of blood circulation of about 300 ~ 800 cc on your legs.
In extreme cases, it seems that earthworms are passing by.
In the long term, if the blood is concentrated in one, inflammation develops well inside the feet.
In this case, it is not desirable for beauty, and if it gets worse gradually, the phlegm of the leg is formed and the skin rotten.