Total protein measurements can reflect nutritional status, kidney disease, liver disease, and many other conditions. If total protein is abnormal, further tests must be performed to identify which protein fraction is abnormal, so that a specific diagnosis can be made.

Total protein is ordered to provide general information about your nutritional status, such as when you have undergone a recent weight loss. It is also ordered 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 (edema).

Low total protein levels can suggest a liver disorder, a kidney disorder, or a disorder in which protein is not digested or absorbed properly. Some laboratories also report the calculated ratio of albumin to globulins, termed the A/G ratio. Normally, there is a little more albumin than globulins, giving a normal A/G ratio of slightly over 1. Because disease states affect the relative changes in albumin and globulins in different ways, this may provide a clue to the physician as to the cause of the change in protein levels. A low A/G ratio may reflect overproduction of globulins (such as seen in multiple myeloma or autoimmune diseases) or underproduction of albumin (such as occurs with cirrhosis) or selective loss of albumin from the circulation (as occurs with nephrotic syndrome). A high A/G ratio suggests underproduction of immunoglobulins (as may be seen in some genetic deficiencies and in some leukemias). More specific tests, such as albumin, liver enzyme tests, and serum protein electrophoresismust be performed to make an accurate diagnosis.

PLEASE NOTE: Numerically reported test results are interpreted according to the test's reference range, which may vary by the patient's age, sex, as well as the instrumentation or kit used to perform the test. A specific result within the reference (normal) range – for any test – does not ensure health just as a result outside the reference range may not indicate disease. To learn more about reference ranges, please see the article, Reference Ranges and What They Mean. To learn the reference range for your test, consult your doctor or laboratorian. Lab Tests Online recommends you consult your physician to discuss your test results as a part of a complete medical examination.

Prolonged application of a tourniquet during blood collection can result in a blood sample that has a higher protein concentration than the rest of the circulation. This will mean that the test result for total protein will be falsely elevated (higher than the actual concentration in the circulation). Drugs that may decrease protein levels include estrogens and oral contraceptives.