For children less than three years of age, the normal range is broader, 2.9–5.5 g/dL.Low albumin (hypoalbuminemia) may be caused by liver disease, nephrotic syndrome, burns, protein-losing enteropathy, malabsorption, malnutrition, late pregnancy, artefact, genetic variations and malignancy.High albumin (hyperalbuminemia) is almost always caused by dehydration. In some cases of retinol (Vitamin A) deficiency, the albumin level can be elevated to high-normal values (e.g., 4.9 g/dL) because retinol causes cells to swell with water. (This is also the reason too much Vitamin A is toxic.) This swelling also likely occurs during treatment with 13-cis retinoic acid (isotretnoin), a pharmaceutical for treating severe acne, amongst other conditions. In lab experiments it has been shown that all-trans retinoic acid down regulates human albumin production. Pathology
Hypoalbuminemia
Hypoalbuminemia means low blood albumin levels. This can be caused by:

Liver disease; cirrhosis of the liver is most common
Excess excretion by the kidneys (as in nephrotic syndrome)
Excess loss in bowel (protein-losing enteropathy, e.g., Ménétriers disease)
Burns (plasma loss in the absence of skin barrier)
Redistribution (hemodilution [as in pregnancy], increased vascular permeability or decreased lymphatic clearance)
Acute disease states (referred to as a negative acute-phase protein)
Malnutrition and wasting
Mutation causing analbuminemia (very rare)
Anorexia nervosa (most common cause in adolescents)In clinical medicine, hypoalbuminemia significantly correlates with a higher mortality rates in several conditions such as heart failure, post-surgery, COVID-19. Hyperalbuminemia
Hyperalbuminemia is an increased concentration of albumin in the blood. Typically, this condition is due to dehydration. Hyperalbuminemia has also been associated with high protein diets. Medical use
Human albumin solution (HSA) is available for medical use, usually at concentrations of 5–25%.
Presence of reactive oxygen species (ROS), can induce irreversible structural damage and alter protein activities. Loss via kidneys
In the healthy kidney, albumins size and negative electric charge exclude it from excretion in the glomerulus. This is not always the case, as in some diseases including diabetic nephropathy, which can sometimes be a complication of uncontrolled or of longer term diabetes  in which proteins can cross the glomerulus. The lost albumin can be detected by a simple urine test. Depending on the amount of albumin lost, a patient may have normal renal function, microalbuminuria, or albuminuria. Interactions
Human serum albumin has been shown to interact with FCGRT.It might also interact with a yet-unidentified albondin (gp60), a certain pair of gp18/gp30, and some other proteins like osteonectin, hnRNPs, calreticulin, cubilin, and megalin. See also
Bovine serum albumin
Serum albumin

References
Further reading
External links
Human Albumin structure in the Protein data bank
Human Serum Albumin on the Human Protein Reference Database
Albumin binding prediction
Albumin at Lab Tests Online
Albumin: analyte monograph from the Association for Clinical Biochemistry and Laboratory Medicine
Overview of all the structural information available in the PDB for UniProt: P02768 (Serum albumin) at the PDBe-KB.