When the blood pressure is not high enough to deliver adequate blood flow to the organs of the body, the organs may be damaged. (drlam.com)
As the problem progresses, respiration difficulties due to the enlarged stomach and a loss of adequate blood flow through the heart (decreased cardiac function due to pressure on the large vena cava and hepatic veins that returns blood to the heart) result in hypoxia (inadequate oxygen), shock and collapse. (2ndchance.info)
They ensure your ankles and feet are compressed enough to get adequate blood flow and not swell too much. (thefashionablehousewife.com)