-Malnutrition
-Liver failure-Damage to Kidneys etc.
The plasma proteins are present in the blood they are interesting because they are heavy molecules, so they generally don't leave the blood vessels ie. The veins, arteries and capillaries.
The osmotic pressure of the plasma proteins(called Oncotic pressure) is responsible for decreasing the amount of water that leaves the arterial side and also for increasing the amount of water that the veins suck in, a decrease in the level of plasma proteins can cause generalised body swelling as it will decrease the amount of water sucked in from venous side and increase the amount of water that leaves the arterial side.
How can the level of plasma proteins decrease?
- A decrease in the production can cause it, ie. Liver Failure as Plasma proteins are mostly produced in the Liver.- Damage to kidneys which leads to the excretion of proteins in the Urine.
- Malnutrition can also cause generalised body swelling as it makes it difficult for the body to produce plasma proteins. (There is marked difference if you look at a baby with Kwashiorkar and a baby with Marasmus).
Generalised Swelling can be caused due to a lot of reasons but it is particularly difficult to treat generalised body swelling caused due to reduced amounts of plasma proteins because, reduced concentration of plasma proteins reduces oncotic pressure and causes fluid to remain outside the blood vessels, this causes swelling of the body and also reduces the blood volume.
The body copes up with reduced blood volume by many mechanisms of which a very important mechanism is the reduction in the amount of urine the bodies passes out, this is done by Renin Angiontensin Aldosterone System. But the actual problem here is not reduced fluid in the body but reduced oncotic pressure, and the activation of Renin Aldosterone Angiontensin System actually dilutes the Blood plasma proteins even further and can exacerbate swelling by increasing the total amount of fluid that is there in the body by decreasing urine outflow and by diluting plasma proteins. This is why it is particularly difficult to treat edema caused due to Liver Cirrhosis.
From the above discussion it is clear that Liver Cirrhosis causes Increased Aldosterone in our body, Diuretics that work by Antagonising the effects of Aldosterone are of particular importance. Spironolactone is a commonly used Aldosterone antagonist which is used in conjunction with other medicines because Spironolactone has a few very serious life threatening side effects.
-Syed Moris
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