Guide to Total Protein

WRITTEN BY

The Levels Team

Updated: 05/22/2025|12 min read

Summary

Proteins are complex molecules made of amino acid chains that serve as building blocks throughout the body. Blood proteins, measured in this test, are specialized proteins that support the transportation of substances through the body and serve as indicators of kidney and liver health.

Why It Matters

While blood proteins are primarily composed of albumin and globulins, the value of total protein comes from seeing it alongside these individual measurements in your comprehensive panel. Albumin, produced by the liver, helps maintain fluid balance and transport substances through blood. Globulins, made by both the liver and immune system, include various proteins that support immune function and transport. Total protein levels reflect liver function, kidney function, immune status, and nutritional balance. Dehydration or fluid overload can also influence results.

Discrepancies between total protein and its components (albumin and globulin) can indicate laboratory error, dehydration, or abnormal protein production (e.g., paraproteins in multiple myeloma). However, this is relatively rare - more commonly, discrepancies between total and individual proteins indicate either measurement issues or the need to look more closely at liver and kidney function, nutritional status, or inflammation.

Think of total protein as a cross-check - it helps validate the individual protein measurements and occasionally catches unusual patterns that warrant further investigation. This is useful because protein abnormalities often appear before other symptoms appear, making this combination of measurements a helpful screening tool for various conditions.

Clinical Ranges

Lab Reference Ranges:

• 1-19 Years: 6.3-8.2 g/dL
• ≥20 Years: 6.1-8.1 g/dL

Lifestyle Factors That Can Impact It

While some lifestyle factors can impact total protein, the body will work to preserve levels. Often, it takes a more dramatic health issue to affect total protein.

Factors that can have a positive impact include:

• Balanced protein intake from diverse dietary sources provides the complete amino acid profile needed for protein synthesis
• Regular exercise (moderate intensity) stimulates protein production while maintaining healthy protein turnover
• Adequate hydration maintains proper blood volume and protein concentration

Factors that can lower blood protein levels:

• Poor dietary protein intake limits available amino acids for blood protein synthesis
• Extreme dieting causes the body to break down proteins for energy
• Overtraining or overexercising increases protein breakdown beyond the body's ability to replace

Other Factors That Can Impact Levels

Genetic Factors

• Inherited disorders of protein metabolism: Usually decreases, depending on the specific disorder
• Genetic variations in liver function: Usually decreases, depending on variation

Medical Factors

• Any etiology of liver failure can cause lowered total protein
• Renal insufficiency or failure can alter total protein
• Corticosteroids: Often increase albumin production
• Exogenous hormones like testosterone and estradiol can increase proteins
• Estrogens: Can decrease serum proteins
• IV fluids: Temporarily decreases through dilution; fluid overload (e.g., congestive heart failure, kidney disease) can also dilute total protein
• Blood transfusions: temporarily increase but usually not clinically significant
• Recent surgery: Typically decreases due to increased protein needs for healing

Testing Accuracy and Stability

Protein tests are reliable under proper test conditions, but some considerations can affect results.

Factors That Can Affect the Accuracy of Your Test 

• Dehydration changes blood volume and concentration
• Recent strenuous exercise
• Taking medications and supplements listed above. Inform the lab of all medications.

What It Means In Relation to Other Blood Markers

Your medical provider will interpret total protein results alongside other markers:

• Albumin: Important for evaluating nutritional status and liver function
• Globulin: Includes important immune system proteins and can indicate inflammation, infection, or cancer
• Prealbumin: A more sensitive marker for recent nutritional status compared to albumin
• C-Reactive Protein (CRP): An inflammatory marker that can be elevated when total protein is high
• BUN/Creatinine: Important for assessing kidney function, which can affect protein levels

What Results May Mean in the Context of Other Markers

• High total with normal albumin/globulin: May indicate the presence of abnormal proteins.
• Low total with normal ratio: May indicate overall protein loss or dilution.
• Normal total with abnormal ratio: Can indicate underlying process.
• High total with high globulins: May indicate inflammation or immune activation.
• Low total with low albumin: Can suggests either liver dysfunction or protein loss.

Follow-up Considerations

You should always talk to your doctor if you have medical concerns or questions.

When Re-Testing May be Appropriate

• Normal levels: Annual testing if stable
• Mildly abnormal: Every 3-6 months while addressing underlying causes
• Significantly abnormal: immediate followup testing
• Additional testing after significant changes (diet, medications, treatments)

Additional Testing Your Doctor May Consider

Mildly abnormal:

• Comprehensive metabolic panel
• Liver function tests
• Nutritional assessment
• Inflammatory markers

Significantly abnormal:

• Serum protein electrophoresis
• Immunoglobulin levels
• Kidney function tests
• Complete nutritional workup

Bibliography