Albumin blood test: what low or high albumin means

What albumin measures

Albumin makes up most of the protein in your blood. It holds water inside blood vessels, so when it is low, fluid can leak into tissues and cause swelling. It also carries hormones, vitamins, enzymes, calcium and many medicines.

It is reported with total protein and globulin on a CMP. Because the liver makes it, albumin is also read as a sign of how well the liver is working. See the albumin lab guide and the liver function panel.

What a low albumin can mean

• Liver disease, such as cirrhosis or hepatitis, since a damaged liver makes less.
• Kidney disease, which can let albumin leak into the urine.
• Inflammation or infection. Albumin falls when the body is fighting illness.
• Not enough protein, from malnutrition or digestive conditions that block absorption, such as Crohn's or celiac disease.
• Large burns and thyroid disease.
• Pregnancy. A lower albumin is normal in pregnancy.

Albumin can also drop after 24 to 48 hours without eating, and birth control pills can lower it.

What a high albumin can mean

A high albumin usually means dehydration, for example from severe diarrhea or not drinking enough. Less water in the blood makes albumin look higher. Some medicines, including steroids, insulin and hormones, can also raise it.

Gabriel's optimal band tops out at 5.0 g/dL for this reason. Above that, a recheck when well hydrated makes more sense than reading it as extra health.

How albumin changes other results

• Calcium. Much of your calcium rides on albumin. A low albumin makes total calcium read low, about 0.8 mg/dL for each 1 g/dL drop. See calcium.
• Anion gap. Albumin carries much of the unmeasured negative charge. A low albumin lowers the anion gap by about 2.5 mEq/L per 1 g/dL and can hide a real problem. See anion gap.
• A/G ratio. A low albumin lowers the albumin to globulin ratio.

What to do with an abnormal result

1. Read it with liver enzymes, kidney tests and a urine albumin test (UACR). That shows whether the liver, kidneys or something else is the likely cause.
2. Ask about inflammation markers such as CRP, since inflammation lowers albumin.
3. Think about recent illness, fasting, pregnancy and medicines, all of which can shift the result.
4. Recheck a high albumin when well hydrated.

See a clinician promptly if a low albumin comes with swelling in your legs, belly or around the eyes, foamy urine, yellowing of the skin or eyes, dark urine, unexplained weight loss, or shortness of breath.