Microalbuminuria is a term to describe a moderate increase in the level of urine albumin. It occurs when the kidney leaks small amounts of albumin into the urine, in other words, when there is an abnormally high permeability for albumin in the glomerulus of the kidney. The term 'microalbuminuria' is now discouraged by KDIGO (Kidney Disease Improving Global Outcomes) and has been replaced by 'moderately increased albuminuria'.