A major protein formed by the liver. It is the main constituent of total protein; the remaining fraction is called globulin. It is the major protein that circulates in the bloodstream. As it is made by the liver and secreted into the blood it is a sensitive marker and a valuable guide to the severity of liver disease. And chronic liver disease causes a decrease in the amount of albumin produced. Albumin levels are decreased in chronic liver disease, such as cirrhosis. It is also decreased in nephrotic syndrome, where it is lost through the urine.