Question

Why does decreased serum albumin result in edema?

Answer 1

To understand the reason (pathology ) hypoalbuminaemia and edema , it will be easy once we understand this simple relation of body constituents and its pressure .

Ø The human body is composed of appx , consist of

62 percent water,

16 percent fat,

16 percent protein,

6 percent minerals,

and less than 1 percent carbohydrate,vitamins etc .

Ø In that 16% of protein, albumin is the major protein found in our body which is 55-60% of human albumin plasma.

Ø We know that human cell is made up of cytoplasm , which majorly proteins and lipids .

Ø So , this protein ,ie albumin plays a major role as constituents of hormones , free radicals get attached to albumin to be active (eg Calcium binds to albumin)

Ø Albumin is synthesized in the liver.

Ø Therefore any pathology condition of liver will affect the albumin level in the body i.e. in case of   liver failure , cirrhosis or chronic hepatitis.

Ø The role of albumin –

·      All the constituents dissolved in the body has some osmotic pressure (molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.)

·      The total oncotic pressure capillary =28 mmHg

albumin contribute appx= 22 mmHg of this oncotic pressure.

·      Large plasma proteins cannot easily cross through the capillary walls , therefore the oncotic pressure of capillary beds tends to draw water into the vessels. (balance out the tendency for fluid to leak out of the capillaries)

·      But in condition of low serum albumin level , there is disruption in the oncotic pressure , the fluid tend to leak out of the capillary causing EDEMA

# hope the explaination satisfies your question. cheers .