Albumin is a protein that is produced in the liver and released into the blood. It helps prevent blood from leaking out of blood vessels, carries medicines and other substances through the blood, and is important for tissue growth and healing.

When albumin levels drop, fluid may collect in the ankles (pedal edema), lungs (pulmonary edema), or abdomen (ascites). Many things can cause low albumin levels. The most common causes include liver disease, a poor diet (malnutrition), severe burns, kidney disease, gastrointestinal malabsorption syndromes, Hodgkin's lymphoma, diabetes, hyperthyroidism, rheumatoid arthritis, lupus, or heart failure.