Total protein test explained

Total protein in the blood is the sum of two main groups of proteins: albumin and globulins. Albumin maintains the fluid balance in the blood vessels and transports various substances, while globulins include antibodies and other proteins that take part in the immune system and in clotting. Albumin and some of the globulins are made in the liver, while other globulins are made by the immune system, which is why the total protein test is often used together with other liver markers to assess liver function. The test also helps to assess nutritional status and how the kidneys are working, because protein can be lost in the urine or through the gastrointestinal tract. The amount of total protein by itself does not show which fraction (albumin or globulins) has changed - that requires an albumin test or a protein fractions (electrophoresis) test.

• During a routine health check or a biochemistry blood panel (to assess liver or kidney function)
• When there is tiredness, weakness, unexplained weight loss or a reduced appetite
• When liver disease is suspected - with abdominal pain, swelling, or yellowing of the skin and eyes
• When kidney disease is suspected, or to keep an eye on swelling (oedema)
• When there is nausea or blood in the urine

A raised total protein means that the albumin or the globulin portion has increased. According to MedlinePlus, this can be a sign of an infection (for example HIV or viral hepatitis) or of multiple myeloma; raised globulins also occur with an acute infection, acute or chronic inflammation (for example rheumatoid arthritis) and chronic liver disease. A protein fractions (electrophoresis) test helps to establish the exact cause.

• Infections - for example HIV or viral hepatitis
• Multiple myeloma (a cancer of blood cells)
• Acute or chronic inflammation, an acute infection, chronic liver disease - other causes of raised globulins

What to discuss with a doctor:

• A protein fractions (electrophoresis) test - to establish which fraction has changed
• Inflammatory markers (CRP) and liver function tests
• A consultation with a family doctor about further investigation, if the result recurs

A low total protein

A low total protein is linked to liver or kidney disease, poor nutrition, or protein lost through the gastrointestinal tract. According to MedlinePlus, the causes include liver cirrhosis, nephrotic syndrome and impaired protein absorption.

• Liver cirrhosis or other impaired liver function
• Nephrotic syndrome (a kidney disease)
• Poor nutrition, not enough calories, vitamins or minerals
• Impaired protein absorption in the gastrointestinal tract, or protein lost through it (for example coeliac disease)

What to discuss with a doctor:

• Liver function tests (ALT, AST, bilirubin) and kidney function markers
• An assessment of nutritional status
• A urine test for protein loss (proteinuria)

Total protein is the sum of albumin and globulins. Albumin makes up the greater part of that amount and maintains the fluid balance, while globulins include antibodies and other immune proteins. To tell apart which fraction has changed, a separate albumin test or protein fractions test is done.

Which tests it is assessed with

Total protein is often assessed together with albumin, liver function markers (ALT, AST, bilirubin) and kidney markers, because it helps to assess how the liver and the kidneys are working, as well as overall nutritional status.