Human serum albumin is a protein found in plasma. It is created in the liver. It has several functions, including the transportation of hormones and fats.
Low albumin levels can be caused by liver damage, overactive kidneys, burns and malnutrition.
High albumin levels are usually due to dehydration.
It also has a pharmaceutical use to replace albumin lost due to trauma, burns or surgery.
Human serum albumin at Wikipedia