A urine microalbumin test can detect very small levels of a blood protein (albumin) in your urine. It is used to detect early signs of kidney damage in people who have a risk of kidney disease.Healthy kidneys filter waste from your blood while retaining healthy components, such as proteins like albumin. Kidney damage can cause proteins to leak through your kidneys and out of your body through your urine. Albumin (al-BYOO-min) is one of the first proteins to leak when the kidneys are damaged.Microalbumin tests are recommended for people with an increased risk of kidney disease, such as those with type 1 diabetes, type 2 diabetes or high blood pressure.