What is the meaning of Oedema?

In some pathological conditions the body is in a positive water balance; that is the intake of fluids is greater than the excretion, and the patient is said to have oedema. Oedema results when the body water- is increased to the levels of 10% or more above normal. We had learnt in the earlier section that plasma proteins exert oncotic pressure that helps to retain water within blood vessels, thus preventing its leakage from plasma into the interstitial spaces. In certain disease states as in Kwashiorkor, the protein content of the plasma is exceptionally low, water leaks into the interstitial spaces causing oedema. Oedema is one of the classical symptoms of kwashiorkor, and this has already been covered in the unit on Proteins. Dietary treatment with proteins of high biological value should be initiated to correct this. In contrast to the oedema arising due to a dietary protein deficiency in PEM, the oedema noticed in Nephrotic syndrome results due to an increased permeability of the glomerular capillary; the plasma proteins, which are normally retained in the blood, escape into the urine causing proteinuria. With a loss of plasma proteins in the urine, blood proteins fall sharply, giving rise to oedema. Congestive cardiac failure (CCF) and cirrhosis of the liver are examples of conditions with a disturbance in sodium excretion, namely sodium excretion is reduced thereby contributing to the retention of water. Treatment will involve restriction in the amount of salt with/ without fluid restriction in the diet. At times, diuretics may be used to facilitate fluid excretion. Fluid loss secondary to diarrhoea has been responsible for thousands of deaths of children in developing countries. Oral rehydration therapy (ORT).with a simple mixture of water, salts and sugar has been highly effective in reducing the number of deaths.