Total Serum Protein

The test measures total protein in serum, the liquid part of blood. This consists mainly of albumin and globulins, which include antibodies. Results are a general indicator flagging changes, for example in liver or kidney disease, dehydration or chronic inflammation; further tests investigate the cause.

Who the test is for

• people having general check-ups and those having liver function assessed, alongside other liver tests;
• people with swelling, unexplained fatigue or weight loss;
• people with suspected kidney disease causing protein loss in urine;
• people with persistent diarrhoea or poor nutrient absorption;
• people whose doctor suspects chronic inflammation or a disease increasing antibody production.

What the test indicates

Blood proteins have different functions. Albumin, the most abundant, is produced by the liver: it keeps fluid in blood vessels and transports many substances. Globulins are a varied group. The liver produces some, while immune cells produce immunoglobulins, or antibodies.

Total protein is the sum of all these proteins. When albumin is also measured, a doctor can calculate globulins from the difference and the albumin-to-globulin ratio (A/G ratio). Normal total protein does not always mean everything is normal: albumin may be low and globulins high, leaving the total unchanged.

Preparation and sample

Total protein is measured in venous blood. Fasting is not required for this test alone, but if glucose or blood lipids are also tested that day, come in the morning after fasting. Drink water as usual before sampling: significant dehydration temporarily raises the value, while large amounts of intravenous fluid dilute blood and lower it.

How results are interpreted

Total protein is expressed in g/L. The adult reference interval is usually approximately 66 to 81 g/L, but depends on age and method; use the interval printed on your report. Mild abnormalities often have little significance. A doctor interprets results alongside albumin, liver tests, kidney findings and your symptoms.

High total protein

• Dehydration is the most common cause of mild elevation: less fluid in blood makes proteins more concentrated.
• Chronic inflammation and infections, such as chronic hepatitis, HIV or autoimmune diseases, when the body produces more antibodies.
• Chronic liver disease: in cirrhosis, albumin falls and globulins rise, so total protein may be normal or elevated.
• Multiple myeloma and Waldenström’s macroglobulinaemia are less common causes. One group of cells produces large amounts of one antibody. This is suspected when globulins are markedly elevated, and the next step is protein electrophoresis.

Low total protein

• Liver disease, when the liver produces less albumin.
• Kidney disease, particularly nephrotic syndrome, with protein loss in urine. A doctor then requests total urine protein and creatinine.
• Bowel disease and poor absorption, for example untreated coeliac disease or inflammatory bowel disease.
• Severe malnutrition, extensive burns and serious chronic illnesses.
• Blood dilution, for example in pregnancy, when mildly lower values are expected.

How to arrange testing

You can have blood taken without an appointment or referral at one of our branches across Croatia (listed on the Contact page). Prices for all tests and panels are available in the service price list. Total protein is also included in the Extended Liver Health Panel, alongside AST, ALT, AP, GGT and total bilirubin.

Frequently asked questions

What is the difference between total protein and albumin?

Albumin is one protein, the most abundant in blood, while total protein is the sum of albumin and all globulins. The tests are therefore often performed together: both results are needed to see whether a change reflects low albumin or excess globulins.

What does high total protein with normal albumin mean?

Globulins are probably elevated. This occurs in chronic inflammation or infection, liver disease and autoimmune disease, and less often in conditions producing large quantities of one antibody. A doctor assesses whether protein electrophoresis is needed.

Is high total protein a sign of cancer?

In most cases, no. The most common cause of mild elevation is dehydration, followed by chronic inflammation. Multiple myeloma is a rare cause, suggested only by further tests such as protein electrophoresis alongside blood count, calcium and kidney findings.

Can I raise total protein through diet?

Blood total protein is not a measure of dietary protein intake. If low because of liver, kidney or bowel disease or inflammation, it improves when the cause is treated. Diet matters in true malnutrition, as assessed by a doctor.