Definition A total protein test measures the total amount of protein in the blood. It is used as a screening process to diagnose a number of illnesses, including kidney disease and liver disease.
There are two major types of proteins in the blood: albumin and globulin. A change in the level of either type of protein may cause an abnormal total protein value. Albumin is produced in the liver, and helps keep the blood fluids within the blood vessels. When albumin is low, fluid may escape the vessels and cause swelling in the body. Globulins are formed by the liver and by the immune system. Globulins have many functions. Most important, they help the body defend itself against infections.
Who is a candidate for the test? Total protein may be measured for many different reasons. For example, a doctor may measure total protein if he or she suspects or finds:
If the amount of total protein is abnormal, more tests may be done.
How is the test performed? In order to measure the amount of total protein in blood serum, a blood sample is taken. The blood is usually taken from a vein in the forearm or hand. The blood is then sent to the laboratory for testing.
What is involved in preparation for the test? Specific instructions are available from a doctor. Generally, no preparation is required.
What do the test results mean? Normally, protein levels in the blood serum range from around 60 to 78 grams per litre. These values are different in younger children.
Author: Kimberly Tessmer, RD, LD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 26/05/2005 Contributors Potential conflict of interest information for reviewers available on request