Albumin – Understanding Your Blood Test Result

Section Editor: Christopher McCudden Ph.D., DABCC, FADLM, FCACB
September 23, 2026

Albumin is the most abundant protein in your blood, and it is made only by the liver. It helps keep fluid in your blood vessels and carries many substances throughout the body. Albumin is measured as part of a liver panel and a comprehensive metabolic panel, usually printed beside a total protein result.

This article explains what the albumin test measures and why a low albumin is so often unrelated to the liver. It also covers what high and low results mean, why the value reflects the past few weeks rather than today, and what your doctor is likely to do next.

The reference range that applies to your result is the one printed on your laboratory report, not the typical ranges shown here. Reference ranges vary between laboratories based on the equipment used, the population tested, and individual factors such as age, sex, and pregnancy status. Always compare your result to the reference range printed on your own report, and discuss any abnormal (or unexpectedly normal) result with your doctor.

What does the albumin test measure?

The albumin test measures how much albumin is circulating in your blood. Albumin accounts for roughly half of all the protein in blood plasma. The liver produces it continuously, and no other organ can make it.

Albumin does two main jobs. It creates the pull that keeps fluid inside blood vessels rather than leaking into surrounding tissue, which is why very low levels cause swelling. It also acts as a carrier, transporting calcium and bilirubin through the bloodstream, along with hormones and many medications.

Why a low albumin usually is not about the liver or about food

Low albumin is one of the most common abnormal results on a blood panel, and the two explanations patients assume first are usually wrong. Albumin falls in almost any illness because laboratories call it a negative acute-phase reactant. During an infection, an injury, or an operation, the liver shifts its production toward other proteins and makes less albumin. Blood vessels also become leakier, so albumin escapes into the surrounding tissues. Both effects can drop albumin within a day or two, depending on what a person is eating and what their liver is like.

This is also why albumin is a poor measure of nutrition. Guidelines from the American Society for Parenteral and Enteral Nutrition state that albumin should not be used to diagnose malnutrition, because inflammation lowers it regardless of what someone eats.

The timing matters too. Albumin survives in the blood for about three weeks, so the value reflects the previous two to three weeks rather than the current day. It falls quickly when someone becomes unwell, but it recovers slowly afterward. A low result in the weeks after an illness or operation is often just the tail end of that recovery.

How is the albumin test performed?

Albumin is measured from a routine blood sample and is rarely ordered on its own. A technologist collects blood from a vein, usually in your arm, and you don’t need to fast. The laboratory measures albumin using a dye that binds to it and changes color.

Two things about the draw itself can shift the result. Lying down before the sample lowers albumin slightly because fluid redistributes, while leaving a tourniquet on too long raises it. Neither effect is large, but both can move a borderline result across the line.

What do albumin results mean?

Your albumin result is read against the reference range printed on your own report, and alongside the other results measured with it. The figures below are typical for adults.

A normal albumin. Most adults fall between approximately 3.5 and 5.0 g/dL (35 to 50 g/L), although some laboratories use a slightly wider range.
A mildly low albumin. A result slightly below the range is common and often reflects a recent illness, an operation, or ongoing inflammation rather than a liver problem.
A markedly low albumin. Below roughly 2.5 g/dL (25 g/L), albumin no longer holds fluid in the blood vessels effectively, and swelling of the ankles, abdomen, or face can appear.
The albumin to globulin (A/G) ratio. Some reports include this calculated value, normally around 1.1 to 2.5. When it is flagged low, the cause is usually the low albumin itself rather than a separate problem.
A high albumin. No disease raises albumin. A high result nearly always means the blood was concentrated, usually by dehydration or by a tourniquet left in place too long.

What conditions and factors can affect albumin?

Albumin falls when the liver makes less of it, when it leaks out of the bloodstream, or when the body loses it. Several of these can happen at once.

Inflammation and acute illness. Infection, injury, and surgery all lower albumin within days, as do flares of inflammatory conditions. This is the most common explanation by a wide margin.
Long-term liver disease. In cirrhosis, the liver cannot manufacture enough albumin. This is usually a late change, appearing after much liver tissue has been replaced by scar.
Loss through the kidneys. When kidneys leak protein into the urine, blood albumin falls. Foamy urine is the sign patients most often notice.
Loss through the intestine. Celiac disease, Crohn’s disease, and other conditions that inflame the bowel lining can allow protein to escape into the gut.
Dilution. Intravenous fluids, pregnancy, and heart failure increase the volume of fluid in the circulation, which lowers the measured concentration without any albumin loss.
Extensive burns or severe skin disease. Albumin is lost directly through damaged skin.
Severe or prolonged undernutrition. This lowers albumin, but it is rarely the only cause, and isolated low albumin in an otherwise well person is not evidence of it.

Because albumin drops in so many situations, a low result on its own suggests something is going on, but not what it is. Its value comes from reading it alongside the other results on the same report.

What other tests are ordered with albumin?

Albumin is interpreted alongside the tests measured with it, and each one narrows the list of possible explanations.

Total protein and globulin. Globulin is calculated by subtracting albumin from total protein, and the balance between the two separates several causes.
The liver enzymes. ALT and AST show whether liver cells are injured, while ALP and GGT show whether the bile ducts are involved. Low albumin with normal enzymes argues against liver disease as the cause.
Inflammatory markers. A raised C-reactive protein alongside a low albumin usually confirms that inflammation is driving the result.
Urine protein testing. This test identifies albumin being lost through the kidneys.
Calcium. Much of the calcium in blood travels attached to albumin, so a low albumin makes the total calcium look low even when the active calcium is normal. Your doctor corrects for this rather than treating the calcium result at face value.

What happens after an albumin test?

For a mildly low albumin in someone who has recently been unwell or had surgery, the usual step is to repeat the test after a few weeks. Albumin recovers slowly, so repeating it too soon often shows no change and isn’t very informative.

If albumin stays low without an obvious explanation, your doctor will look for where it is going. That usually means testing the urine for protein, reviewing liver results, and checking inflammation markers. A referral follows only if one of those points to a specific cause.

Some symptoms are worth reporting, no matter what the number shows. New swelling in the ankles or abdomen, and persistently foamy urine, both need attention. You should also mention unexplained weight loss to your doctor.

Questions to ask your doctor

What was my albumin, and what is the reference range at this laboratory?
Were my liver enzymes and total protein normal on the same test?
Could a recent illness, injury, or operation explain this result?
Should my urine be tested for protein?
Was my calcium result corrected for my albumin level?
Could any of my medications be involved?
How does this compare with my previous albumin results?
When should this test be repeated?
Does this result change anything about my treatment or my medication doses?
What symptoms should prompt me to contact you before my next appointment?