Albumin is a protein that is present in the blood. When the kidneys are working properly, only tiny amounts of albumin pass from the bloodstream into the urine. In kidney failure (the last stage of a slow process of decline in kidney function) large amounts of protein leak into the urine. A long time before this amount of damage, small changes in the kidney allow very small, but abnormal amounts of albumin to leak through, often as a result of having diabetes. Too little albumin is present to be detected by the usual simple urine test strip (sometimes called a protein dipstick). This is termed microalbuminuria because of the low but significant concentration of albumin in the urine, not because it is a smaller type of the protein. Microalbuminuria is usually simply called albuminuria.See MoreSee Less
