From the Guidelines
A workup for low hemoglobin (anemia) should begin with a complete blood count with differential, peripheral blood smear, reticulocyte count, iron studies (serum iron, ferritin, total iron binding capacity), vitamin B12, and folate levels, as recommended by the most recent guidelines 1.
Initial Evaluation
The initial evaluation of anemia should include:
- Complete blood count with differential to determine the severity of anemia and identify any underlying conditions
- Peripheral blood smear to evaluate red blood cell morphology
- Reticulocyte count to assess bone marrow response to anemia
- Iron studies, including serum iron, ferritin, and total iron binding capacity, to evaluate iron deficiency
- Vitamin B12 and folate levels to assess for deficiencies
Additional Testing
Additional tests may include:
- Comprehensive metabolic panel to assess kidney function and liver enzymes
- Stool occult blood test to check for gastrointestinal bleeding
- Endoscopy for GI bleeding, if suspected
- Hemolysis workup, if suggested by lab values
- Bone marrow biopsy, if suspected primary bone marrow disorders
Treatment
Treatment of anemia depends on the underlying cause:
- Iron deficiency: oral iron supplementation with ferrous sulfate 325 mg three times daily, taken with vitamin C to enhance absorption and between meals to maximize effectiveness 1
- B12 deficiency: cyanocobalamin 1000 mcg daily orally or as monthly injections
- Folate deficiency: folic acid 1 mg daily
- Severe anemia (hemoglobin <7 g/dL) with symptoms may require blood transfusion
Importance of Identifying Underlying Cause
It is essential to identify and address the underlying cause of anemia, as treatment depends on the specific cause. Anemia is not a diagnosis but a manifestation of an underlying condition, and proper treatment depends on identifying and addressing the specific cause 1.
From the Research
Workup for Low Hemoglobin
- A low hemoglobin level, commonly referred to as anemia, requires a systematic approach to determine the underlying cause and provide the correct treatment 2.
- The diagnosis of iron deficiency anemia is still complicated, and most tests have drawbacks, but reticulocyte hemoglobin content (CHr) has been shown to be a useful indicator of iron availability and an early marker of iron deficient erythropoiesis 3.
- CHr can be used in screening for iron deficiency, diagnosis of iron deficiency anemia, and diagnosis of functional iron deficiency anemia in acute or chronic diseases or inflammation 3.
- A study of 260 adult patients with anemia of chronic disease, iron deficiency anemia, and chronic renal failure found a significant correlation between CHr and hematological and biochemical parameters for iron status 4.
- In cases of severe anemia, such as a critically low hemoglobin level of 1.4 g/dL, further diagnostic workup may be necessary to determine the underlying cause, such as menometrorrhagia or other conditions leading to iron deficiency 5.
- The approach to diagnosis should include a systematic evaluation of the patient's history and laboratory values, using an algorithm to navigate the diagnostic process and avoid overlooking potential causes of low hemoglobin level 2.
- Treatment options may include iron supplementation, blood transfusions, and other therapies depending on the underlying cause of the anemia 6.