Blood test

Normal proteins level in the blood

Blood test
Normal proteins level in the blood
Last update: 19/10/2020

What are normal protein levels in the blood?

  • Adults: 6 - 8.3 g/dL
  • Preterm newborns: 4.2 - 7.6 g/dL
  • Term newborns: 4.6 - 7.4 g/dL
  • Children up to 1 year old: 6 - 6.7 g/dL
  • Children over 1 year old: 6.2 - 8.0 g/dL

In the International System of Units (SI), proteins in the blood are measured in g/L. The normal protein levels in the blood in the SI are:

  • Adults: 60 - 83 g/L
  • Preterm newborns: 42 - 76 g/L
  • Term newborns: 46 - 74 g/L
  • Children up to 1 year old: 60 - 67 g/L
  • Children over 1 year old: 62 - 80 g/L

Why normal levels can differ across different labs?

Each laboratory must establish its own normal ranges for proteins in the blood. These ranges depend on the makeup of the local population, the technologies used and the accuracy of the measurement. There may be also slight differences in the normal levels, according to age, gender, race or ethnic origin, geographic region, diet, type of sample and other relevant status.

Your doctor will study the results along with your medical record, screenings, physical condition, symptoms and any other relevant information about your situation.

What is the role of proteins in the blood?

Proteins are structural components of cells and tissue. Some proteins also circulate in blood plasma with different roles.

There are two main groups of proteins in the blood:

  • Albumin: Composes 60% of blood plasma proteins. Albumin serves as a transport protein carrying large organic anions (fatty acids, hormones, etc.) and helps maintain capillary permeability.
  • Globulins: They are produced by the immune system to protect the body from germs. They also play an important role in blood clotting. There are different types of globulins:
    • Alpha 1 globulins
    • Alpha 2 globulins
    • Beta globulins
    • Gamma globulins

The albumin/globulin ratio should be greater than 1 because albumin composes the 60% of blood proteins and globulins only the 35% to 40%.

What is the proteins blood test for?

The main purposes of a protein blood test are:

  • Evaluate nutritional deficiencies
  • Provide information on the kidney function
  • Provide information on the liver function
  • Detect malabsorption of proteins

If the total protein values are out of normal range it is necessary to study in detail each group of proteins for a better diagnosis.

High levels of proteins in the blood may be a sign of dehydration, inflammatory disorders or some types of cancer. Low levels of proteins in the blood may be a sign of renal dysfunction or gastrointestinal disorders.

The albumin/globulin ratio must be greater than 1. If it is less than 1 it may be a sign of autoimmune diseases where there are many globulins present in the blood.

If total proteins are below the normal range and albumin is also below the normal range it may be a sign of a rheumatic disease or a collagen disease.

Where can I find more information about protein levels in the blood?

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Which values are considered normal protein levels in the blood?

The following values are considered to be normal values:

IMPORTANT: These levels are expressed in g/dl. They are an example of a healthy man of about 45 years old with a balanced diet, no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.

6 g/dl6.1 g/dl6.2 g/dl6.3 g/dl6.4 g/dl6.5 g/dl6.6 g/dl6.7 g/dl
6.8 g/dl6.9 g/dl7 g/dl7.1 g/dl7.2 g/dl7.3 g/dl7.4 g/dl7.5 g/dl
7.6 g/dl7.7 g/dl7.8 g/dl7.9 g/dl8 g/dl8.1 g/dl8.2 g/dl8.3 g/dl
Medically reviewed by our Medical staff on 19/10/2020


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