Serum Albumin

Serum albumin is the most abundant protein found in human blood plasma and plays a vital role in maintaining normal physiological function. Produced by the liver, albumin helps regulate oncotic pressure, transports hormones, medications, fatty acids, and other substances, and contributes to maintaining fluid balance between the bloodstream and surrounding tissues.

Measurement of serum albumin is a routine laboratory investigation performed in hospitals, primary care, and outpatient settings. It provides valuable information about a patient’s overall health and is frequently used alongside other blood tests to assess liver function, nutritional status, kidney disease, inflammation, and chronic illness.

Low serum albumin, known as hypoalbuminaemia, may result from a variety of conditions. Common causes include chronic liver disease, nephrotic syndrome, protein-losing enteropathy, malnutrition, severe infection, inflammation, burns, and major surgery. Reduced albumin levels are often associated with poorer clinical outcomes in hospitalised patients and may indicate significant underlying disease rather than a nutritional deficiency alone.

Elevated serum albumin is less common and is usually associated with dehydration or significant fluid loss rather than excessive protein production. In most cases, addressing the underlying cause restores albumin concentrations to the normal range.

Serum albumin is an important variable in several validated clinical calculators and scoring systems. One of its most common applications is the calculation of corrected calcium, where albumin concentration is used to estimate the physiologically active calcium level when total serum calcium is affected by abnormal protein binding. Albumin is also included in liver disease assessment tools and nutritional screening methods used throughout clinical practice.

Although serum albumin provides valuable diagnostic information, it should never be interpreted in isolation. Results must be considered alongside the patient’s clinical presentation, medical history, examination findings, and other laboratory investigations. Factors such as acute illness, inflammation, hydration status, and chronic disease can all influence albumin concentrations.

For healthcare professionals, serum albumin remains an important biomarker that supports diagnosis, risk assessment, medication management, and interpretation of several clinical calculators. Understanding its role and limitations helps ensure that laboratory results are interpreted accurately and within the appropriate clinical context.