A patient presentation for anemia may be in the form of a lab value or symptoms of anemia. This clinical mind map is designed for the lab value of anemia. Clinicians often encounter a lab value in the form of low hemoglobin with or without a patient’s symptoms. This anemia mind map provides an approach to solving this lab presentation. Probable diagnoses are chunked based upon the morphology of red blood cells, microcytic, normocytic and macrocytic which helps a clinician narrow down the list of differential diagnoses early in the process. Red cell indices are often included in the initial set of labs, which helps a clinician divide the differentials for anemia based upon red cell morphology.

            This clinical mind map is divided into part 1 representing micro and macrocytic anemias, and part 2 representing normocytic anemias. Helpful mnemonics to memorize differentials on the part 1 of the Anemia mind map are SIT-MIG and HLV for micocytic anemias and macrocytic anemias respectively. Diagnoses which involve a defect in red blood cell production with normal iron metabolism and storage (Thalassemia, Siderolblastic anemia, and Lead toxicity) are typically seen in pediatric populations. The remaining diagnoses typically affect adult populations. The normocytic anemias presented in part 2 includes 3 broad categories based upon hemolysis, which are diagnoses involving no hemolysis, intravascular hemolysis, and extravascular blood loss. If a retic count is available on lab values, a clinician can narrow differentials to which category must be pursued in the evaluation process. However, a clinician should remember that the retic count may not rise quickly enough in response to acute blood loss. Peripheral blood smear can provide valuable information and must be ordered whenever hemolytic anemias are being considered. Helpful mnemonics to memorize differentials are SAMA and GGAP-RAP. These include differentials on part 2 of the Anemia mind map. Gastrointestinal blood loss is listed under categories of both normocytic as well as microcytic anemia because gastrointestinal blood loss typically gives rise to microcytic anemia, but the resulting anemia may then be normocytic if blood loss is rapid or acute. In addition, chronic medical conditions can give rise to microcytic or normocytic anemia based upon dynamics of iron metabolism. Chronic liver disease / cirrhosis, also a chronic medical condition, often results in macrocytic anemia because of accompanying Vitamin B 12 and folate deficiencies.

            Urgent/emergent situations include extremely low hemoglobin, which can result from several acute or chronic etiologies of anemia, and this is reflected in the form of abnormal vital signs, shortness of breath, extreme fatigue, and appearance of distress. There is no one number in grams/dl for hemoglobin which is set to result in an urgent/emergent situation, because in case of chronic anemia, patients are likely to physiologically adapt to low levels of circulating hemoglobin, develop slowly progressive symptoms such as fatigue, and seek advice at some point before their disease process creates an urgent/emergent situation, although their hemoglobin may be quite low. In contrast, patients with acute anemia (acute hemolysis, hemorrhage) may present with urgent/emergent situation, even when their hemoglobin values may not be extremely low.

            Weighing and removing anchor bias involves reviewing risk factors, clinical features, associated physical exam features and additional lab findings for all pathologies. An understanding of epidemiology is helpful in arriving at the diagnosis efficiently

Important Notice:

This website and its contents are for the purposes of general information and education only and are not to be used for diagnosis or treatment without the supervision of a healthcare provider.

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