American Board of Internal Medicine (ABIM) Certification Practice Exam

What urinalysis finding suggests blood in the urine without erythrocytes?

1. Hematuria

2. Hemoglobinuria

3. Proteinuria

4. Glycosuria

The correct answer is: Hemoglobinuria

The correct answer is hemoglobinuria, which indicates the presence of free hemoglobin in the urine rather than intact red blood cells (erythrocytes). This finding typically arises from conditions where red blood cells break down in the bloodstream, leading to the release of hemoglobin, which is then filtered by the kidneys and appears in the urine. It can occur in various medical situations, such as hemolytic anemias, rhabdomyolysis, or severe infections leading to hemolysis. Hematuria, on the other hand, specifically refers to the presence of intact red blood cells in the urine and is typically associated with conditions affecting the urinary tract, such as trauma, infection, or stones. Proteinuria relates to the presence of excess protein in the urine, often linked to kidney issues or certain systemic diseases, but does not indicate blood or hemoglobin. Glycosuria refers to the presence of glucose in the urine, which is commonly seen in the context of diabetes mellitus or other conditions leading to elevated blood glucose levels, and is unrelated to blood findings. Thus, the unique characteristic of hemoglobinuria is its indication of hemoglobin without the presence of erythrocytes, making it the correct choice in this