What Is Albumin?

An Essential Component of Blood Plasma Produced in the Liver

albumin test

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Albumin is the most common protein found in blood plasma. It helps ensure blood stays in arteries and veins and helps carry hormones, vitamins, and enzymes throughout the body. This substance is produced in the liver and quickly conveyed to the bloodstream.

Low albumin levels in the blood indicate serious liver and kidney problems, and elevated levels, known as hyperalbuminemia, can be a sign of dehydration, diarrhea, or other conditions. Doctors will often measure albumin levels in diagnosing or treating conditions.

In emergency medicine, albumin is used for fluid resuscitation, a procedure that replenishes bodily fluids in cases of severe bleeding, sweating, or other issues.

Albumin in the Body

Proteins are some of the most important substances in the body and are intimately involved in numerous bodily processes. Among these, albumin plays several important and essential role in several processes and bodily systems:

  • Blood plasma: Because of its larger molecular size, albumin is able to attract water and other molecules, which helps ensure proper blood pressure in the veins.
  • Ligand delivery: Ligands are molecules produced in the body that are essential for the cellular and chemical involved in the function of bodily systems.
  • Drug synthesis: This molecule also carries certain drugs—considered “exogenous” or outside ligand—through the bloodstream. These include methadone, propranolol, thiopental, furosemide, warfarin, methotrexate, alfentanil, and many others.

Abnormal Albumin Levels

Given the many important roles that albumin plays in the body, abnormal levels of this protein can not only cause health problems but be signs of other issues. That said, in other, rarer cases, healthy people will have abnormal levels.

What might abnormal albumin levels mean? Here’s a quick breakdown:

  • Kidney problems: Impaired kidney function, especially chronic kidney disease (CKD) leads to lower than normal levels. Kidney disease can also result in albumin spilling into the urine, known as microalbuminuria.
  • Liver diseases: Lower levels of albumin are also seen in cases of liver diseases, such as hepatitis (an inflammation of the liver, often due to viral infection) and liver cirrhosis (scarring of liver tissue due to chronic hepatitis or excessive alcohol use), jaundice (a yellowing of eyes and skin) and others.
  • Crohn’s disease: A persistent and damaging inflammation of the gastrointestinal tract, Crohn’s disease leads to difficulties absorbing nutrients. In these cases, albumin levels are lower than normal.  
  • Celiac disease: Diminished levels are also seen in cases of this autoimmune disorder, in which foods with gluten, such as wheat, barley, or rye, cause white blood cells to attack the lining of the small intestine.
  • Thyroid disease: A host of diseases can affect the thyroid gland, which can cause immune system problems. These issues lead to lower levels of albumin.  
  • Whipple disease: This rare bacterial infection affects joints and the digestive system, impairing the body’s ability to digest food. In these cases, albumin levels will be lower than normal.
  • Malnutrition: Decreased levels of albumin in the blood may also be signs of malnutrition.
  • Dehydration: Insufficient water in the body will cause albumin levels to be elevated.
  • Weight loss surgery: Following weight loss surgery, which reduces the body’s ability to absorb nutrients, albumin levels may be elevated.
  • High protein diet: In those whose diet is very high in protein, lower levels of albumin are seen.
  • Medications and therapies: Some medications, including insulin, hormones, or steroids will raise levels; whereas others, such as birth control pills, will lower them.

The Albumin Blood Test (ALB)

The albumin blood test is usually recommended if liver or kidney dysfunction is suspected. It is also part of standard screening of sugar levels and digestive health called a comprehensive metabolic panel (CMP), which is often a component of an annual physical.

During the Test

For the test, a sample of blood drawn from a vein in the person’s arm. It is safe and well-tolerated, with only a sting when the needle pierces the skin. Other than some potential bruising, there are no risks when samples are collected safely. Results typically take some time as the blood may need to be sent off to a separate facility for testing.

Interpreting Results

A healthy range for albumin in blood supply is defined as between 3.4 and 5.4 grams per deciliter (g/dL), though there may be some variations based on the testing facility. If your results fall outside of this range, your doctor will know that you may have liver, kidney, or other digestive issues.

Keep in mind that this doesn’t necessarily mean you have health problems; as noted, taking certain drugs may raise or lower these levels. Following abnormal results—and along with data from other tests—the doctor will be able to consider the next steps in diagnosis or treatment.

This may mean imaging and additional diagnostic testing if kidney, intestinal, or liver problems are suspected, analysis of diet and nutrition, and, if needed, pharmaceutical or surgical treatment. When getting your ALB test results, don’t hesitate to ask your doctor to explain what they mean.  

Fluid Resuscitation

Another major use of albumin is in fluid resuscitation, a procedure that replaces blood or other bodily fluids in emergency situations. In this procedure, regulated amounts of albumin solution is delivered directly to the body via an intravenous line (IV).

While there is some debate about the clinical efficacy of this approach as compared to others, this protein’s ability to improve pressure inside veins—as well as its shorter half-life—make it an option worth considering.

What sorts of conditions are taken on with fluid resuscitation? Here’s a quick breakdown:

  • Hypovolemic shock: Resuscitation is most often employed in cases of hypovolemic shock, which is when the body has lost 20% or more of its blood volume. As such, this approach is part of treatment for puncture wounds or other injuries.
  • Sepsis: This very dangerous condition is a system-wide inflammation caused by an immune response. It leads to a range of symptoms, including fever, difficulty breathing, low blood pressure, fast heart rate, and confusion. If untreated, this disease can harm multiple organ systems. 
  • Liver transplant: Fluid resuscitation with albumin is often also necessary during liver transplantation.
  • Liver problems: If a patient has liver problems, such as cirrhosis or hepatitis, and requires fluid resuscitation, albumin solution is considered a salient option.

A Word From Verywell

Albumin is an important part of the body. It's also an essential medical tool, both as a marker of health and as a means of treatment. When you see results for an albumin test in your medical record, ask your doctor if you have any questions as to its significance.

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