Albumin Blood Test: What Low and High Results Mean

What Albumin Does in the Blood

Blood consists of fluid and blood cells. Albumin keeps the fluid part of your blood from leaking out of your blood vessels and into other body tissues.

If your body does not have enough albumin, fluid can leak out of your blood vessels. That fluid can build up in your lungs, your abdomen, or other parts of your body. Albumin also helps carry important substances throughout your body, including hormones, vitamins, and enzymes.

On your lab paperwork, this test may appear under other names. Common alternative labels include ALB or the serum albumin test.

What the Albumin Blood Test Is Used For

Healthcare providers use an albumin blood test to check your general health, assess your nutrition, and see how well your liver and kidneys are functioning. It is also used to monitor treatment for liver or kidney conditions or other conditions that may affect albumin levels.

Your doctor may order the test if you show signs of liver disease. Liver disease symptoms include nausea, vomiting, lack of appetite, fatigue, weakness, jaundice (yellowing of the skin and eyes), swelling or pain in the abdomen, swelling in the ankles and legs, dark urine, light-colored stool, and frequent itching.

A provider may also order the test if you show symptoms of kidney disease. Kidney disease symptoms include swelling in the hands and feet or puffy eyelids, dry skin, itching or numbness, fatigue, increased or decreased urination, bloody or foamy urine, loss of appetite and weight loss, muscle cramps, and trouble thinking clearly. With chronic kidney disease (CKD), symptoms often do not appear until the condition reaches its later stages.

Low Albumin Causes

A lower than normal albumin level may be a sign of liver disease, kidney disease, malnutrition, or other conditions. Your doctor will interpret a low result alongside other blood markers to determine the underlying cause.

Common causes of low albumin include:

• Liver disease, including severe cirrhosis, hepatitis, and steatotic liver disease.
• Kidney disease, which allows albumin to spill out of the blood and into the urine.
• Malnutrition, particularly an inadequate intake of protein in your diet.
• Digestive diseases that impair protein absorption or use, such as Crohn's disease and malabsorption disorders.
• Infection or thyroid disease.
• Severe burns covering a large area of the body.

An out-of-range value does not always indicate a medical disorder that requires treatment. Albumin levels drop naturally during pregnancy, after fasting for 24 to 48 hours, or while taking certain medications such as birth control pills.

High Albumin Levels

A higher than normal albumin level may be a sign of dehydration.

Dehydration may be caused by severe diarrhea or other conditions.

Certain medications can also increase your blood albumin levels. Prescription medicines such as steroids, insulin, and hormone treatments can raise your measured values.

Albumin Blood Test vs Urine Albumin

An albumin blood test measures the concentration of protein circulating in your bloodstream, whereas a urine albumin test checks whether protein has leaked through your kidneys into your urine.

A healthy kidney does not let albumin pass from the blood into the urine. When kidney filters suffer damage, they allow albumin to pass into the urine, a condition known as albuminuria. For more details on the full panel of kidney markers, see our guide to the kidney function test and our overview of eGFR test results.

Providers screen for kidney damage using a urine dipstick followed by a urine albumin-to-creatinine ratio test. A ratio above 30 mg/g is considered higher than normal. To learn more about related tests, see our guide to foamy urine and our review of routine urinalysis.

Total Protein and the A/G Ratio

A total protein and albumin/globulin (A/G) ratio test measures all proteins in your blood and compares the amount of albumin to the amount of globulin. Albumin makes up the largest share of total blood protein, while the remaining portion consists of globulins.

According to MedlinePlus, globulins help fight infections and transport nutrients through the body. The liver produces some globulins, while the immune system produces others.

Laboratories frequently report the A/G ratio as part of a routine comprehensive metabolic panel. This test can help check how well the liver and kidneys are working and whether you are lacking some nutrients.

Preparing for an Albumin Blood Test

A blood albumin test requires no special physical preparation when ordered on its own. A healthcare professional draws a small blood sample from a vein in your arm using a fine needle, a process that typically takes under five minutes.

You may feel a slight sting when the needle enters your arm, and minor bruising or tenderness can occasionally appear at the puncture site.

If other blood tests were ordered, you may need to fast for several hours; your provider will say. Certain medicines can affect results, so tell your provider what you take, but do not stop any medicine without talking with your provider first.

Next Steps After Your Albumin Result

An albumin blood test alone cannot diagnose any disease or health condition. Your provider usually considers your albumin level with other test results.

If your result falls outside the normal range, discuss the findings directly with your healthcare provider. Review your complete panel alongside your doctor, and use our guide to blood test results to prepare your questions about your albumin blood test.

Where to Find Metabolic Panel Test Kits