Total protein is the combined concentration of all the proteins in the blood plasma. It is made up of two large fractions: albumin (about 60%) and globulins.
Blood proteins do a great deal: they maintain the fluid pressure in the vessels, carry hormones and drugs, and take part in immunity and clotting. So total protein is a basic indicator of nutrition and of liver and kidney function.
Reference ranges
The reference range depends on the lab; a typical range for adults:
| Normal | 64 – 83 g/L |
| High (hyperproteinemia) | dehydration, chronic inflammation, myeloma |
| Low (hypoproteinemia) | liver disease, loss through the kidneys, undernutrition |
| Interpreted with the fractions | albumin / globulins |
What an elevated level means
A high total protein is most often relative — from blood thickening in dehydration.
A true rise occurs in chronic inflammation and infection (globulins rise), and in some blood diseases — for example, multiple myeloma, when an abnormal protein is produced. So a persistently high total protein needs clarification by the fractions.
What a low level means
A low total protein (hypoproteinemia) is a more common and more significant finding.
Causes: liver disease (reduced synthesis of albumin), protein loss through the kidneys (nephrotic syndrome) or gut, inadequate nutrition and malabsorption, severe burns. Low protein leads to edema and reduced defenses.
How the test is done
Total protein is measured in a biochemistry blood test from a vein, preferably fasting. Marked dehydration inflates the result, so ordinary sampling conditions matter.
On its own the value is not very informative: it is interpreted together with albumin and globulins (the protein fractions), and if needed with liver and kidney tests.
What affects the value
- Dehydration — inflates total protein (blood thickening).
- Liver disease — reduces protein synthesis.
- Loss through the kidneys and gut — lowers it.
- Undernutrition and malabsorption — lower it.
- Chronic inflammation — raises it (via the globulins).
- Pregnancy — may lower it through blood dilution.
Frequently asked questions
What is total protein made of?
Of two main fractions: albumin (about 60%) and globulins. Albumin keeps fluid in the vessels and handles transport, while globulins handle immunity and the carrying of substances. So total protein is always assessed together with these fractions.
What does a low total protein mean?
Most often liver disease, protein loss through the kidneys or gut, inadequate nutrition or malabsorption. Low protein leads to edema and reduced immunity, so it needs the cause clarified by the fractions and other tests.
Is a high total protein dangerous?
More often it is dehydration (blood thickening). But a persistent true rise occurs in chronic inflammation and, less often, in blood diseases such as myeloma. Protein fraction analysis (electrophoresis) helps sort it out.
Related terms
Sources
- MedlinePlus (NIH) — Total Protein Test
- Serum Total Protein — StatPearls (NCBI)
- MedlinePlus (NIH) — Protein Blood Test