What is being tested?

The total protein test measures the concentration of all the proteins in the plasma portion of your blood. Proteins are important building blocks of all cells and tissues; they are important for body growth and health. Total protein measures the combined amount of two types of proteins, albumin and globulin. Albumin moves many small molecules through the blood but its main purpose is to keep fluid from leaking out of blood vessels, while globulin proteins include enzymes, antibodies and more than 500 other proteins.

How is it used?

Total protein measurements can reflect someone's nutritional status, the presence of kidney disease and liver disease, as well as many other conditions. If total protein is abnormal, further tests may be needed to identify which protein fraction is abnormal, so that a specific diagnosis can be made.

When is it requested?

Total protein is measured along with several other tests to provide information if you have symptoms that suggest a liver or kidney disorder, or to investigate the cause of abnormal pooling of fluid in tissue (oedema). It will also be requested as part of the investigation of multiple myeloma.

What does the result mean?

If total protein results are abnormal further tests will be required to identify the cause. Low total protein levels can suggest a liver disorder (the liver is an important producer of many plasma proteins), a kidney disorder (proteins may be lost from the circulation into the urine due to a kidney disorder) or a disorder in which protein is not digested or absorbed properly. Low total protein concentrations may sometimes be seen in patients with deficiency of the immune system. More specific tests, such as albumin and liver enzyme tests must be performed to make an accurate diagnosis.

Mildly higher total protein levels can be due to dehydration or infection and inflammation and high total protein levels may be due to some types of blood cancer that lead to an accumulation of an abnormal protein (such as multiple myeloma) or to long-term liver disease.

Reference intervals

Adult
60- 80 g/L

The reference intervals shown above are known as a harmonised reference interval. This means that eventually all laboratories in Australia will eventually use this same interval so wherever your sample is tested, the reference interval should be the one shown above. Laboratories are in the process of adopting these harmonised intervals so it is possible that the intervals shown on the report of your results for this test may be slightly different until this change is fully adopted. 

Is there anything else I should know?

Prolonged application of a tourniquet or standing during blood collection can increase total protein levels.

Many medications may affect total protein levels, including oestrogens, steroids, and oral contraceptives. Tell your healthcare practitioner all the prescription or over-the-counter medications, supplements, or illicit substances you may be taking.

Common questions

• Can I test for protein levels at home?

No, there is no home test available.

More information

RCPA Manual: Protein