A 47-year-old woman presents with dizziness for the past two days and fatigue. She has pale nailbeds and a 1/6 systolic ejection murmur. Pulse 98/min, blood pressure 101/58 mmHg; oxygen saturation 100% on room air. Which test is most likely to determine the diagnosis?

• A. Erythrocyte sedimentation rate
• B. ECG
• C. POC Hgb Level
• D. Serum thyroid-stimulating hormone

Answer: (C)

Suspected anemia from pallor and fatigue is best confirmed by measuring how much hemoglobin is in the blood. A point-of-care hemoglobin level quickly shows whether the patient is anemic and how severe the anemia is, which directly guides management and further testing (such as iron studies, ferritin, and reticulocyte count). The normal oxygen saturation indicates the problem isn’t lack of oxygen in the lungs or blood, but rather reduced oxygen-carrying capacity from low red blood cells. The other tests don’t directly diagnose anemia: ESR is a nonspecific marker of inflammation, TSH could explain fatigue in some contexts but not pallor or a flow murmur, and an ECG can reveal rhythm or ischemic issues but won’t establish whether anemia is present.