What is a total protein test?
Albumin and globulin are two types of protein in your body. The total protein test measures the total amount albumin and globulin in your body. It’s used as part of your routine health checkup. It may also be used if you have unexpected weight loss, fatigue, or the symptoms of a kidney or liver disease.
Proteins are important building blocks of all cells and tissues. Proteins are necessary for your body’s growth, development, and health. Blood contains albumin and globulin. Albumin proteins keep fluid from leaking out of your blood vessels. Globulin proteins play an important role in your immune system.
A total protein test is completed as part of your routine health checkup. It’s one of the tests that make up your comprehensive medical panel (CMP). It may be ordered if you have:
- unexplained weight loss
- edema, which is swelling caused by extra fluid in your tissues
- symptoms of kidney or liver disease
The total protein test measures the total amount of protein in your blood and specifically looks for the amount of albumin and globulin.
This test will also look at the ratio of albumin to globulin in your blood. This is known as the “A/G ratio.”
The test uses a blood sample that’s analyzed in the laboratory. To get a blood sample, a healthcare provider will draw blood from a vein in your arm or the back of your hand. First, they’ll clean the site with an antiseptic wipe. They’ll wrap a band around your arm to apply pressure to the area and gently insert the needle into the vein. The blood will collect into a tube attached to the needle. Once the tube is full, the band and the needle will be removed from your arm. They’ll put pressure on the puncture site to stop any bleeding.
In infants or small children, a lancet is used to puncture the skin and the blood collects in a small glass pipette, test strip, or onto a slide. A bandage may be placed over the area if there’s any bleeding.
You don’t need to make any special preparations before the test is done. Your doctor will let you know if you should avoid food or drinks before the test.
Many medications can affect the total protein test results. Talk to your doctor about your current medication use before you take this test.
Medications that can affect the test results include:
You may feel moderate pain or discomfort from the blood test. The risks associated with having a blood test are minimal. In some cases, you may experience:
- excessive bleeding
- fainting or feeling light-headed
- developing a hematoma, which occurs when blood gathers under your skin
There is a risk of infection any time your skin is broken.
Total protein range
The normal range for total protein is between 6 and 8.3 grams per deciliter (g/dL). This range may vary slightly among laboratories. These ranges are also due to other factors such as:
- test method
Your total protein measurement may increase during pregnancy.
If total protein is abnormal, additional tests must be performed to identify which specific protein is low or high before a diagnosis can be made.
Elevated total protein may indicate:
- inflammation or infections, such as viral hepatitis B or C, or HIV
- bone marrow disorders, such as multiple myeloma or Waldenstrom’s disease
Low total protein may indicate:
- liver disorder
- kidney disorder, such as a nephrotic disorder or glomerulonephritis
- malabsorption conditions, such as celiac disease or inflammatory bowel disease
- extensive burns
- agammaglobulinemia, which is an inherited condition in which your blood doesn’t have enough of a type of globulin, affecting the strength of your immune system
- inflammatory conditions
- delayed post-surgery recovery
Low albumin is considered albumin below 3.4 g/dL. It’s associated with decreased effectiveness of medications used for ulcerative colitis. Low albumin levels may result in complications during or after surgery.
Normally, the A/G (albumin to globulin) ratio is slightly higher than 1. If the ratio is too low or too high, additional testing must be done to determine the cause and diagnosis. If the ratio is low, it can suggest:
- autoimmune disease
- multiple myeloma
- kidney disease
A high A/G ratio can indicate genetic deficiencies or leukemia. Make sure to discuss your results with your doctor. They may want to do follow-up testing.