When the veins get saggy and the one way valves which direct the blood back to the heart become pushed far apart, this leads to the valves themselves becoming incompetent which aggrivates the situation even further. So, if the blood collects a lot in the veins, so that the blood returning back to the heart is less, this will effect the filling of the heart. It can eventually lead to low blood pressure, the person will feel dizzy and weak and may faint. Plasma is present in the blood stream. It is the fluid that carries the pink or blue blood cell where it needs to go in the body.
Plasma molecules are smaller than the blood cells.
Under pressure the smaller plasma molecules are allowed to filtrate out of the blood vessels causing swelling in the ankles. The plasma molecules have a straw yellow color which is why swollen ankles can appear slightly yellow in color. The amount of blood ejected by the each heartbeat is reduced. To make up for the fact that each heart beat is now delivering less blood to the brain, the heart starts to beat faster. Now if each heartbeat is delivering only 1 ounce, the heart has to beat at 120 beats per minute, to sustain the same amount of blood flow to the body.