From the Guidelines
For a patient with anemia and significant weight loss, I recommend a comprehensive workup starting with complete blood count with differential, peripheral blood smear, reticulocyte count, iron studies (ferritin, transferrin, iron, TIBC), vitamin B12, folate, and hemolysis markers (LDH, haptoglobin, bilirubin) as suggested by the KDIGO guideline 1.
This approach is supported by the British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults, which recommend taking a detailed history and initial investigation of confirmed IDA should include urinalysis or urine microscopy, screening for coeliac disease, and in appropriate cases, endoscopic examination of the upper and lower GI tract 1.
Additional tests should include:
- Comprehensive metabolic panel
- Thyroid function tests
- Inflammatory markers (ESR, CRP)
- Stool tests for occult blood
- Endoscopy and colonoscopy to evaluate for gastrointestinal malignancy or bleeding sources
- Chest X-ray and abdominal imaging (CT or ultrasound) to screen for malignancies
Consider specific tests based on clinical suspicion, such as:
- Celiac disease antibodies
- HIV testing
- Bone marrow biopsy if blood disorders are suspected
This comprehensive approach is necessary because the combination of anemia and weight loss raises concern for serious underlying conditions, including malignancy, chronic inflammation, malabsorption syndromes, or chronic blood loss, as highlighted in the British Society of Gastroenterology guidelines 1. Early diagnosis is critical as these symptoms often indicate advanced disease requiring prompt intervention. The most recent and highest quality study supporting this approach is the 2021 British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults 1.
From the Research
Initial Evaluation
- A thorough history and physical examination are essential in investigating the cause of anemia 2
- A complete blood cell count (CBC) is a crucial initial test, providing important clues to the classification and cause of anemia 2, 3, 4, 5, 6
Supplemental Tests
- A peripheral blood smear may be necessary to examine the morphology of red blood cells 2, 3
- A reticulocyte count can serve as a useful screen for hemolysis or blood loss 2, 3
- An iron panel, including ferritin and iron levels, total iron-binding capacity, and transferrin saturation, can help identify iron deficiency anemia 2
- Levels of vitamin B12, folate, lactate dehydrogenase, haptoglobin, and bilirubin may also be necessary to determine the cause of anemia 2
Additional Investigations
- Examination of the bone marrow may be required for diagnosis in some cases 3
- Molecular testing is increasingly being used to aid in the diagnostic process 3
- The complete blood count (CBC) can also be used to predict the risk of cardiovascular and metabolic diseases, such as cancer, cardiovascular disease, and type 2 diabetes 4