Albumin is a protein that makes up a large proportion of blood plasma. It
transports fat, hormones and other materials throughout the body, and helps
regulate the movement of fluid into and out of body tissues, so it is necessary
for maintenance of the body. Some people have a low albumin level may present
edema.
The normal value of albumin may vary with different laboratory running the
test. Most labs consider about 3.5~5 grams per deciliter to be normal.
Edema is a condition that fluid remains in the interstitial fluid instead of
returning to the capillaries, leading to swelling.
Transport of fluid is associated with hydrostatic pressure and oncotic
(osmotic) pressure.
Hydrostatic pressure tends to push fluid out of capillaries while ontotic
(osmotic) pressure restrains fluid within the capillaries.
Osmotic pressure is based on the concentration of albumin in the plasma
protein.
With an insufficient plasma concentrations of protein like albumin, there is
a low solute (protein) concentration in the blood and a high "water"
concentration.
Osmosis refers to the movement of water from high water concentration to low
water concentration. Therefore, in case of low albumin levels, the protein
concentration is low (high water concentration), and the osmotic pressure will
be very low. Fluid in the interstitium (tissue) will not return to the
capillaries as normal.
And this is the causes of edema.
Recently, study shows that low albumin level is highly related to the disease
state. Listen to the physician's advice. If the cause is due to disease, it may
be recommended to eat a balanced diet with adequate protein. Kidney diseases or
disorders like glomerulonephritis can also be the reason, as protein get lost
from the body through urine, leading to decreased protein levels. So, treatment
for restoring the renal function is necessary.