The normal range of albumin expected in a microalbumin urine test is less than 30 milligrams in a 24-hour period, according to MedlinePlus. Most albumin, a protein, is not excreted, so the urine sample level should be low.
An abnormal result for a microalbumin urine test is between 30 and 300 milligrams in 24 hours, explains MedlinePlus. This indicates kidney damage, but it does not necessarily reveal the severity of the problem. More tests are needed to determine the extent of the trouble. Most abnormal albumin levels are due to diabetes. However, they are sometimes caused by high blood pressure, narrowing of the kidney artery, certain cancers, or genetic or immune disorders.