It will then act like a magnet for water, continuously attracting more water from the blood to accumulate in the tissue spaces. Others
Swollen legs, feet and ankles are common in late pregnancy. The problem is partly caused by the weight of the uterus on the major veins of the pelvis. It usually clears up after delivery of the baby, and is mostly not a cause for concern, though it should always be reported to a doctor. Lack of exercise is another common cause of water retention in the legs. Exercise helps the leg veins work against gravity to return blood to the heart. If blood travels too slowly and starts to pool in the leg veins, the pressure can force too much fluid out of the leg capillaries into the tissue spaces. The capillaries may break, leaving small blood marks under the skin. The veins themselves can become swollen, painful and distorted – a condition known as varicose veins. Muscle action is needed not only to keep blood flowing through the veins but also to stimulate the lymphatic system to fulfil its "overflow" function. Long-haul flights, lengthy bed-rest, immobility caused by disability and so on, are all potential causes of water retention. Even very small exercises such as rotating ankles and wiggling toes can help to reduce it.Certain medications are prone to causing water retention.
A fall in osmotic pressure occurs in nephrotic syndrome and liver failure.Causes of edema which are generalized to the whole body can cause edema in multiple organs and peripherally. For example, severe heart failure can cause pulmonary edema, pleural effusions, ascites and peripheral edema. Such severe systemic edema is called anasarca. In rare cases, a parvovirus B19 infection may cause generalized edemas.Although a low plasma oncotic pressure is widely cited for the edema of nephrotic syndrome, most physicians note that the edema may occur before there is any significant protein in the urine (proteinuria) or fall in plasma protein level. Most forms of nephrotic syndrome are due to biochemical and structural changes in the basement membrane of capillaries in the kidney glomeruli, and these changes occur, if to a lesser degree, in the vessels of most other tissues of the body. Thus the resulting increase in permeability that leads to protein in the urine can explain the edema if all other vessels are more permeable as well.As well as the previously mentioned conditions, edemas often occur during the late stages of pregnancy in some women. This is more common with those of a history of pulmonary problems or poor circulation also being intensified if arthritis is already present in that particular woman. Women who already have arthritic problems most often have to seek medical help for pain caused from over-reactive swelling. Edemas that occur during pregnancy are usually found in the lower part of the leg, usually from the calf down.