Pressure. Varices develop because of varicose vein walls aren't as elastic as normal vein walls and because their is too much pressure in the veins (this is called venous hypertension). The pressure develops because valves in the veins (which normally keep venous blood flosing in the right direction) have broken. Pressure causes the veins to enlarge. As they enlarge, the already weak vein walls stretch and.
Vein size. As vein gets larger diameter the wall of the vein gets thinner and the overlying skin is stretched and gets thinner also. Therefore easier to break open and bleed.
Varices... ...Happen when venous pressure rises far above normal. As with any overinflated tube, bursting is common.
Bleeding. As varicose increase in size the surrounding skin may become weaker due to the pressure which may dry out the skin.
Vein pressure & thin. Varices are prone to bleeding predominantly due to elevated venous pressure within the abnormal veins. It is like puncturing a water balloon & not expecting it to leak . . . if something is under alot of pressure it will bleed alot when it breaks. In addition, the vein walls are thinned & weakened which leads to easy rupture. Often patients with esophageal varices also have less clotting ability.