What is the reference range for albumin in serum?

• A. 3.5-5.5 g/dL
• B. 2.0-3.0 g/dL
• C. 4.5-6.5 g/dL
• D. 1.5-2.5 g/dL

Answer: (A)

Normal serum albumin in adults is about 3.5–5.5 g/dL. This reference interval comes from measurements in healthy populations and is often expressed as 35–55 g/L. Albumin, produced by the liver, helps maintain plasma oncotic pressure and carries many substances in the blood. Values within this range indicate adequate liver function and normal fluid balance. Levels below 3.5 g/dL can reflect liver disease, nephrotic loss, malnutrition, or inflammation, while higher than 5.5 g/dL is uncommon and may suggest dehydration. So the range 3.5–5.5 g/dL is the standard reference for serum albumin.