Differential Diagnosis of Low Hemoglobin

A low hemoglobin level, commonly referred to as anemia, is frequently encountered in the acute care setting among patients with different comorbidities. It is essential that clinicians understand the pathophysiology of anemia to develop a practical differential diagnosis of the cause of the low hemoglobin level. A systematic approach should be used when determining the diagnosis to provide the correct treatment for the patient.

This article highlights the equal importance of the patient's history and laboratory values in arriving at the correct diagnosis of low hemoglobin level. The approach to diagnosis is described along with an algorithm to enable the clinician to quickly and effectively diagnose their patients.

The differential diagnosis of low hemoglobin level is extensive, and some may be overlooked if an organized approach is not taken. For unstable patients, the diagnosis is usually clearer to the clinician. However, for a stable patient, the diagnosis may be difficult to obtain owing to the many causes of low hemoglobin level. The algorithm allows for easier navigation of the diagnostic process.