Total protein is a measurement of protein in the fluid portion of your blood (serum). Proteins are fundamental building blocks for cells and tissues. They support functions like digestion, blood clotting, energy production, and overall health. This test serves as a general indicator of health, often included in routine check-ups.
Understanding Your Total Protein Level
A total protein test measures two types of proteins in your blood: albumin and globulins. Albumin accounts for over half of the total protein and is produced by the liver. Its main functions include preventing fluid from leaking out of blood vessels and transporting substances, such as hormones, vitamins, and medications.
Globulins are the remaining proteins and are a diverse group with varied functions. They are important for immune system function, fighting infections, and transporting nutrients. Some globulins are produced in the liver, while others are made by the immune system.
The healthy range for total protein in blood serum is between 6.0 and 8.3 grams per deciliter (g/dL), though these ranges can vary slightly among different laboratories. A total protein level of 8.5 g/dL is considered elevated, exceeding the normal range. This suggests a higher concentration of proteins in the blood, which may warrant further investigation.
Common Causes of Elevated Total Protein
An elevated total protein level, also known as hyperproteinemia, can stem from various causes. One common reason is dehydration, where the body loses more fluids than it takes in. This concentrates the blood plasma, leading to an apparent increase in protein levels even if the actual amount of protein remains stable.
Chronic inflammation or infections can also cause elevated total protein, particularly by increasing globulin levels. Diseases like rheumatoid arthritis or inflammatory bowel diseases, or infections such as HIV and hepatitis B or C, trigger an immune response. This response involves the increased production of immunoglobulins, a type of globulin, as the body combats pathogens or manages the inflammatory process.
Bone marrow disorders are also associated with high total protein levels. Multiple myeloma, a cancer of plasma cells, produces abnormal M proteins, which accumulate in the blood and raise total protein. Waldenström macroglobulinemia is another cancer that leads to large amounts of abnormal macroglobulin protein, contributing to elevated levels. Liver disease can also affect protein metabolism, resulting in elevated protein levels.
Next Steps and Further Evaluation
When a total protein level is elevated, consulting a healthcare professional is the next step to determine the cause. An elevated level does not always indicate a serious condition, but it does warrant further investigation. Your doctor will consider your symptoms and medical history to guide the diagnostic process.
Additional tests are often ordered. Serum protein electrophoresis (SPEP) is a common follow-up test that separates and measures different types of proteins in the blood, differentiating various conditions, including monoclonal or polyclonal gammopathies. It can detect abnormal M-proteins associated with conditions like multiple myeloma.
Other diagnostic evaluations may include a complete blood count (CBC) to assess red and white blood cells and platelet counts. Liver function tests (LFTs) and kidney function tests (KFTs) are also performed to evaluate these organs, as they play roles in protein production and elimination. Markers of inflammation like erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) may also be checked. Further tests, such as a bone marrow biopsy or imaging studies, might be necessary depending on initial findings to establish a diagnosis.