Albumin

Albumin is the most abundant plasma protein, synthesized by the liver. It plays a major role in maintaining oncotic pressure and transporting various substances in blood.

1️⃣ Maintenance of Oncotic (Colloid Osmotic) Pressure

Contributes about 75–80% of plasma oncotic pressure

Prevents fluid leakage from blood vessels into tissues

🔎 Clinical significance:

↓ Albumin → Edema

Severe ↓ → Ascites

Seen in liver disease, nephrotic syndrome, malnutrition

2️⃣ Indicator of Liver Function

Albumin is synthesized exclusively in the liver.

🔹 ↓ Albumin suggests:

Chronic liver disease (cirrhosis)

Severe hepatitis

Liver failure

⚠ It reflects chronic liver dysfunction (because albumin has a long half-life ~20 days).

3️⃣ Nutritional Status Marker

Low albumin may indicate:

Protein-energy malnutrition

Kwashiorkor

Malabsorption syndromes

It is often used to assess:

Preoperative nutritional risk

Chronic illness status

4️⃣ Renal Disease Indicator

In conditions like nephrotic syndrome:

Albumin is lost in urine (proteinuria)

Leads to hypoalbuminemia and edema

5️⃣ Transport Function

Albumin transports:

Bilirubin

Fatty acids

Calcium

Hormones (thyroid, steroid hormones)

Many drugs

🔎 Low albumin can alter drug binding → ↑ free drug levels → toxicity risk.

6️⃣ Inflammatory Marker

Albumin is a negative acute phase reactant.

↓ in:

Chronic infections

Trauma

Burns

Malignancy

7️⃣ Hyperalbuminemia

Rare and usually due to:

Dehydration

Hemoconcentration

Summary Table :
Condition Albumin Level
Liver cirrhosis ↓
Nephrotic syndrome ↓
Malnutrition ↓
Burns ↓
Dehydration ↑
Normal Serum Albumin Level:

3.5 – 5.0 g/dL