What is Albumin?
Albumin is the most common protein in the blood plasma. It is produced from the liver from dietary proteins. Albumin in the blood binds water and thereby prevents leakage of fluid into the tissue. It is also an important transporter protein that carries various substances, such as testosterone and calcium around in the bloodstream. Albumin level in the blood is regulated by many factors, including hormones, nutritional status and inflammatory status.
Why is this analysis important?
Albumin levels in the blood can be determined as a part of a general health check to assess liver and kidney function, as well as general nutritional status.
Since albumin is produced by the liver, loss of liver function could lead to decreased production of albumin despite adequate protein intake. Healthy kidneys have filters that do not normally let large protein molecules such as albumin pass through, but if the filters are damaged, albumin may leak from the blood into the urine, causing nonspecific symptoms such as foamy urine, fatigue or swollenness.
Doctors may also order an albumin test if they suspect increased loss of albumin through the gastrointestinal tract due to disease conditions that damage the gastrointestinal mucosa such as inflammatory bowel disease or celiac disease.
In short, it is useful to analyse albumin levels in the blood to:
Detect liver disorders that decrease albumin production
Detect kidney disorders that increase protein loss
Detect intestinal disorders that increase protein loss
Monitor the nutritional status
Investigate the cause of swollenness
The reference range for albumin levels in the blood can be different depending on the laboratory and technique used. Doctors usually also take into account a number of factors when evaluating albumin values.
High albumin levels in the blood may be associated with:
Low albumin levels in the blood may be associated with:
Inflammation or infection
Intestinal disease that lead to protein loss, such as in inflammatory bowel diseases (for example Crohn's disease)
Some hematological diseases
Some autoimmune diseases
Severe burn injury
Poorly controlled diabetes
Low level of albumin (hypoalbuminemia) is highly nonspecific and can have many possible causes. It is not always possible to pinpoint the exact cause without further evaluation by a doctor. Many substances, including hormones, vitamins, minerals and drugs are transported in the blood by albumin. These substances are typically inactive when bound to albumin. High or low albumin levels in the blood can therefore affect the amount of free unbound and thereby active substances present. It is therefore important to take into account the level of albumin in the blood when evaluating values of for example testosterone or calcium.
Tests that include this marker
Tests of the liver's biosynthetic capacity (eg, albumin, coagulation factors, prothrombin time). Lawrence S Friedman, MD. UpToDate Sep 04, 2018.