What is Protein Total?
Also Known As:
Serum Protein A/G Ratio Test
Total Protein Albumin to Globulin Ratio
A total protein test measures the sum of all types of proteins in the blood. Proteins are fundamental to the functioning of the body. The two main types of proteins found in the blood are albumin and globulins.
Measuring the total protein level as well as the ratio of albumin to globulin can help detect several kinds of health problems, including liver and kidney disease as well as nutritional deficiencies.
In many cases, total protein is included with other measurements using the same blood sample in a test like a liver panel or comprehensive metabolic panel. Whether tested alone or in a panel, total protein and the albumin-to-globulin ratio can be involved in the diagnosis, screening, and monitoring of a range of health conditions.
The purpose of a total protein test is to check the levels of proteins in the blood. Too much or too little protein can reflect conditions including liver or kidney disease, infection, inflammation, malnutrition, and cancer. In many cases, the total protein measurement and A/G ratio are included as part of broader tests, such as the liver panel or comprehensive metabolic panel, that offer further information about possible health conditions.
In addition to the total protein level, testing can determine the ratio between types of proteins known as albumin and globulins. The albumin-to-globulin ratio, or A/G ratio, can also be used to look for signs of an underlying health issue.
This testing can be utilized as a part of diagnosis, screening, and/or monitoring:
- Diagnosis happens after you have symptoms and includes tests that work to determine what is causing those symptoms.
- Screening involves tests that look for health problems before they have caused any symptoms. Panel tests including total protein, for example, may be part of routine checkups for people who have a higher risk of developing liver or kidney disease with the hope of detecting problems at an earlier stage.
- Monitoring is testing that is used to follow a person’s condition over time or in response to treatment. Total protein may be measured in repeat tests at regular intervals in people who have known liver or kidney problems. It can also be part of panel tests to check liver and kidney health when taking medications that can affect these organs.
What does the test measure?
A total protein test measures the combined sum of all of the different proteins in the blood.
Proteins are vital to the functioning of virtually all parts of the body. The most common protein in the blood is albumin, which prevents fluid from leaking out of the blood and also carries substances through the body.
Almost all of the other proteins in the blood are globulins. Globulins are formed by the immune system and by the liver. There are several kinds of globulins, but a basic total protein test usually will not measure the amounts of each specific type.
A blood test of total proteins will often directly measure albumin. This allows for a calculation of the number of globulins by subtracting albumin from total protein. It also allows for a calculation of the albumin-to-globulin ratio.
Total protein is often tested as part of a broader blood test. For example, the liver panel measures albumin, total protein, and a collection of enzymes that provide information about liver health.
When should I get a total protein test?
There are no strict guidelines for when a total protein test is performed. Its use depends on your specific circumstances, and in many cases, it is tested as part of a broader panel test.
For diagnosis, total protein may be measured if you have symptoms that could be caused by a liver or kidney problem. Examples of symptoms associated with liver or kidney disease include jaundice, urinary changes, fatigue, unexplained swelling, nausea, vomiting, and abdominal pain.
As a screening test, total protein and the A/G ratio may be part of a liver panel or comprehensive metabolic panel that is done during routine doctor visits for people who have an elevated risk of developing kidney or liver disease.
Diabetes, high blood pressure, or a family history of liver or kidney problems are risk factors that are frequently considered when determining whether screening is appropriate. Studies have not demonstrated that screening is beneficial in people without risk factors, but some doctors may include these tests in blood work done during normal checkups.
A total protein test can be utilized for monitoring liver or kidney health if you have already had an abnormal test result or have been previously diagnosed with an underlying illness. Testing can also help monitor for side effects of prescription drugs that are known to potentially impact the kidney or liver.
How to get tested
A total protein test is typically performed after it has been prescribed by a doctor. The blood sample is normally taken with a blood draw in a hospital, doctor’s office, or similar medical setting.
Can I take the test at home?
Some at-home test kits include total protein and albumin. With these kits, you can collect a blood sample at home with a fingerstick, but the sample must be mailed to a laboratory where the total protein can be measured.