A urine albumin spot test measures the concentration of albumin, a type of protein, in a urine sample. It is typically used to assess kidney function and detect early signs of kidney damage, particularly in individuals with diabetes or hypertension. The test provides a quick indication of albuminuria, where excess albumin is excreted in the urine. Results are often expressed as the albumin-to-creatinine ratio (ACR), aiding in the diagnosis and monitoring of kidney health.