31/05/2025
ALBUMIN: FUNCTION AND LEVELS
AIbumin is the most abundant plasma protein in blood Constitutes approximately 50 percent of total protein in plasma Synthesized by hepatocytes (liver cells)
Functions:
Maintains intravascular oncotic pressure (prevents fluid from leaking into tissues)
○ Carries hormones, ions, and medications (acts as a transport protein)
Blood Composition Diagram (Right Side of Image)
Plasma (top yellow layer): Contains albumin and other proteins
Buffy coat (middle white layer): Contains white blood
cells and platelets
Red blood cells (bottom red layer): Carries oxygen
Abnormal Albumin Levels
Hypoalbuminemia (Low Albumin Levels)
Causes include:
○ Renal loss - protein lost through urine (e.g., nephrotic
syndrome)
Gut loss - protein lost via the gastrointestinal tract (e.g.,
protein-losing enteropathy)
○ Intravascular volume expansion - dilutional effect (e.g.,
fluid overload)
Decreased albumin production - due to liver disease or
malnutrition
Sepsis and critical illness - increased catabolism, capillary leakage
○ Heart failure - may contribute to dilutional hypoalbuminemia
○ Burns - loss of proteins through damaged skin
Nutritional deficiency - inadequate intake of protein
Hyperalbuminemia (High Albumin Levels) Causes include:
Dehydration
most common cause (reduced plasma volume concentrates albumin)
○ Metabolic syndrome - may lead to altered protein
metabolism
Insulin resistance - sometimes associated with elevated
albumin levels
Clinical Relevance
Albumin levels are a critical indicator in:
Liver function tests
○ Nutritional status assessment
○ Chronic illness monitoring
Fluid balance and oncotic pressure monitoring
Altered levels can impact drug dosing since many
medications bind to albumin