What is edema ?
Edema is an accumulation of extracellular fluid in the tissue, leading to a swelling without increase in the number of cells. Known forms of edema, the swelling of the skin by a reaction to a mosquito bite or sting nettle (urticaria) and edema of the lower legs which can have many causes.
Edema causes
If edema is the amount of moisture that is present in the body too large, or the distribution of the moisture present abnormally. Combinations also occur commonly. The control of the water balance is shared by various organs. An important role is there for taking the hypothalamus, heart, and kidneys discarded.
Extracellular fluid
The amount of extracellular fluid is determined by a number of factors:
- The hydrostatic pressure in the veins and capillaries makes intravascular fluid to be squeezed out through the vessel wall.
- The vessel wall is permeable to water but not to larger molecules such as proteins.
- These exert a colloid osmotic pressure, which enables them again attract water from the tissues.
- The pressure in the veins is determined by its degree of filling, and rises when faulty valves in the veins (varicose veins), or if the heart's supply of blood flowing back can not absorb well through whatever cause.
- Muscles, especially in the legs and calves in the press contraction in the veins and pumps empty the contents into the heart - with functioning valves.
- Moisture between the cells and tissues is collected in in lymphatic capillaries that converge to lymphatic vessels which ultimately (in the chest), result in a vein.
Local edema
- in inflammatory reactions, infections and bruises primary touches the vessel wall is damaged, and under the influence of all kinds of substances very locally issued more permeable. Proteins enter from the bloodstream and the colloid osmotic pressure is reduced. There arises edema.
- in allergic reactions are primary substances are released which make the vessel wall more permeable, such as histamine. Same mechanism.
- obstruction of the lymphatic drainage: lymphedema. By congenital or acquired causes the lymphatic function properly. The body swells strongly involved. For example, a thick arm and after surgery and / or radiation therapy for breast cancer, the lymph nodes are removed in the armpit, which inevitably suffer the lymphatic vessels. Also by erysipelas (erysipelas), lymphatic vessels may be damaged and cause lymphedema.
- locally increased venous pressure due to venous insufficiency. Case of varicose veins or in thrombosis in a leg, the pressure in the veins in both legs or a higher than normal, which in turn causes edema is formed.
Generalized edema
- Renal;
- The kidneys are not able to secrete adequate moisture and keeps the body too much water-resistant.
- The kidneys keep protein not enough against (nephrotic syndrome). The colloid osmotic pressure in the blood falls and the whole body is edematous.
- Cardiac;
- The heart can by an inflow obstruction, an outflow obstruction or a faulty pump action not process enough venous blood flowing back. The venous pressure is rising and there will be more moisture from the vasculature. There occurs mainly on edema of the lower legs and the low-lying parts of the body.
- Hepatic;
- The liver is no longer able to produce the proteins in the blood that for the pressure colloid osmotic worry (cirrhosis, liver failure in alcoholism or poisoning).
Also, many otherwise healthy people have a noticeable swelling of the feet, especially if they are older, overweight, a lot of walking or standing, varicose veins, or if it's hot. This does not have a great significance.
Treatment for the swelling of the legs itself is rarely needed, since it gives in most cases only cosmetic complaints. If the cause can be addressed, it goes with the edema is often better. Often called diuretics (water pills) offer relief. But not in all cases helps. It is also for the purpose of side-effects to strongly inadvisable to use only for cosmetology water tablets to use. In severe cases, no treatable cause measures such as high place, bandaging and wearing compression stockings are attempted.