Albuminuria describes the presence of albumin in the urine. Proteinuria reflects kidney problems that cause these proteins, which normally remain in the blood, to be excreted in the urine. Albumin can be detected with a urine strip called the 24-hour urine albumin test, which uses colored areas that react to the presence of protein. If desired, this screening method can be further supplemented with a urinalysis. In this case, the search for albumin in urine is performed in the laboratory using the first morning urine sample and, if necessary, using 24-hour urine collection.