Albumin

You don’t need to fast or make any special preparations for an albumin test. A blood sample will be taken from a vein in your arm.

Inform your doctor about all medications you’re taking, as some drugs can affect albumin levels.

What the test measures

Albumin is a protein made by your liver. It’s the most abundant protein in your blood plasma (the liquid part of blood).

Albumin has several vital jobs:

• Keeps fluid in your blood vessels: albumin acts like a sponge, holding water in your bloodstream and preventing it from leaking into surrounding tissues
• Transports substances: it carries hormones, vitamins, enzymes, drugs, and minerals (like calcium) throughout your body
• Provides nutrition: albumin supplies tissues with nutrients
• Maintains acid-base balance: it helps keep your blood pH stable

Because albumin is made in the liver and kept in the blood by healthy kidneys, its level provides valuable information about both liver function and kidney health.

What your results mean

Low albumin levels (hypoalbuminaemia)

Low albumin is more common than high albumin and usually indicates an underlying health problem.

Liver disease:

Low albumin can suggest liver disease because the liver makes albumin. When the liver is severely damaged (such as in cirrhosis or advanced hepatitis), it can’t produce enough albumin. Your doctor will request liver function tests to determine which type of liver disease might be present.

Kidney disease:

Low albumin can indicate kidney disease, particularly nephrotic syndrome. In this condition, the kidneys’ filtering units (glomeruli) are damaged and allow albumin to leak from the blood into the urine. Your doctor may also test your urine for albumin (microalbumin or urine albumin-creatinine ratio) to confirm this.

Inflammation and infection:

Low albumin is seen in severe inflammation, infections, or shock. The degree of albumin reduction can help indicate how severe the condition is.

Malabsorption and protein loss:

Low albumin can occur in conditions where your body doesn’t properly absorb or digest protein (like Crohn’s disease or coeliac disease) or when large amounts of protein are lost from the intestines (protein-losing enteropathy).

Malnutrition:

Severe or prolonged malnutrition can cause low albumin, though other factors usually contribute as well.

Other causes:

• Burns (albumin leaks through damaged skin)
• Heart failure
• Pregnancy (a normal consequence of increased blood volume)

High albumin levels

High albumin levels are less common and sometimes indicate dehydration. When you’re dehydrated, there’s less water in your blood, making albumin more concentrated.

Causes of dehydration include:

• Not drinking enough fluids
• Severe vomiting or diarrhoea
• Excessive sweating
• Use of diuretics (water tablets)

Normal albumin

Normal albumin levels suggest your liver is producing adequate amounts of this protein and your kidneys are retaining it properly. However, albumin is just one marker of health, and normal results don’t rule out all liver or kidney problems.

If your albumin is low

Your doctor will want to identify the cause. They’ll typically request additional tests based on your symptoms and medical history.

For suspected liver disease:

• Full liver function tests (ALT, AST, ALP, GGT, bilirubin)
• Hepatitis virus tests
• Liver autoantibodies
• Liver ultrasound or other imaging
• In some cases, liver biopsy

For suspected kidney disease:

• Kidney function tests (urea, creatinine, eGFR)
• Urine tests (urine albumin-creatinine ratio, protein, microscopy)
• Kidney ultrasound

For inflammation or infection:

• Inflammatory markers (CRP, ESR)
• Infection screening
• White blood cell count

Treatment will depend on the underlying cause. For instance, liver disease might require medication, lifestyle changes, or specialist care; kidney disease may need blood pressure control and protein restriction; malnutrition requires dietary intervention.

If your albumin is high

High albumin usually indicates dehydration. Your doctor will assess why you’re dehydrated and recommend:

• Increasing fluid intake
• Treating the cause (stopping vomiting/​diarrhoea, adjusting medications)
• In severe cases, IV fluids

Your doctor may retest albumin once you’re rehydrated to ensure it returns to normal.

Monitoring albumin over time

In people with known liver disease, kidney disease, or chronic illness, albumin may be monitored regularly to track disease progression or response to treatment.

Before surgery, albumin levels help assess nutritional status and predict surgical outcomes. Low albumin before surgery may increase complications.

Several factors can affect albumin levels:

• Medications: anabolic steroids, androgens, growth hormones, and insulin can increase albumin levels
• Intravenous fluids: large amounts of IV fluids can dilute blood and lower albumin readings
• Position: albumin is slightly higher when standing than lying down
• Pregnancy: albumin naturally decreases during pregnancy due to increased blood volume
• Hydration status: dehydration raises albumin, overhydration lowers it
• Age: albumin levels may be slightly lower in elderly people

Albumin is rarely tested on its own. It’s usually part of a broader panel of tests.

Commonly tested alongside albumin:

• Total protein: measures all proteins in blood; helps distinguish albumin from globulin problems
• Liver function tests: ALT, AST, ALP, GGT, bilirubin
• Kidney function tests: urea, creatinine, eGFR
• Electrolytes: sodium, potassium, chloride, bicarbonate

Related protein tests:

• Prealbumin: measures nutritional status and response to nutritional support; more sensitive to recent changes than albumin
• Microalbumin (urine albumin-creatinine ratio): detects small amounts of albumin in urine; early indicator of kidney damage
• Protein electrophoresis: separates and measures different blood proteins

For specific causes of low albumin:

• CRP or ESR (inflammation markers)
• Hepatitis screening
• Autoimmune tests
• Nutritional assessments (vitamin and mineral levels)

Albumin accounts for about 60% of the total protein in your blood. The remaining 40% consists of globulins, which include antibodies and other important proteins.

Your liver produces about 12–15 grams of albumin every day. The albumin you have in your blood at any given time has a lifespan of about 20 days before it’s broken down and replaced.

When albumin levels are very low, fluid can leak out of blood vessels into surrounding tissues, causing swelling (oedema). This is why people with severe liver disease or nephrotic syndrome often develop swollen legs and ankles, or fluid accumulation in the abdomen (ascites).

Learn more about liver disease on the NHS website and kidney disease from Kidney Care UK