Types of Anemia: Chart with Algorithm

Anemia is defined as a reduction in the number of red blood cells or hemoglobin, resulting in lower oxygen-carrying capacity. WHO definition of Anemia is- Hemoglobin less than 13gm/dL for Men and less than 12gm/dL for Women. In this post, we will cover the types of anemia chart and how to approach clinical diagnosis with the algorithm.

The diagnosis of anemia depends on lab investigations and a brief approach. However, most fail to achieve this since the textbooks define it in terms of classifications and categories. In this article, we will try to define exactly how to approach it in a specific pattern using a simple diagram.

The first aim is to establish whether the anemia is Microcytic, Normocytic, or Macrocytic. Upon identification, we can easily make out the specific diagnosis in most cases. Here are the types of anemia in a chart. If you need deep insights, follow our article below.

Before we proceed further, here is something I developed while studying the topic thoroughly:

Table of Contents show

Anemia Protocol (Under Development)

If you are a medical student, you can decode the following easily:

Hb?
- High- PRV (Polycythemia Rubra Vera) (Primary- JAK2 + Low/Normal Erythropoietin, Secondary- Smoking + High Erythropoietin)
- Low?- Anemia
  - MCV?
    - Low- TAILS– Thalassemia, Anaemia of Chronic Disease, IDA, Lead poisoning, Sideroblastic anemia
      - Serum Ferritin
        
        High>Thalassemia/Anaemia of Chronic Disease
        
        Low- IDA (increased transferrin and TIBC) (Associated with Plummer-Vinson- IDA + Glossitis + Oesophageal webs)
    - High- Folate/Vitamin B12 Deficiency/Pernicious Anaemia, Autoimmune Haemolytic Anaemia/Hereditary Spherocytosis
      - Reticulocytes? (Markers of Haemolysis- LDH, Indirect Bilirubin, Reticulocytes, Polychromasia, Decreased Haptoglobins)
        
        High- Autoimmune Haemolytic Anaemia/Hereditary Spherocytosis/G6PD Deficiency
        
        Spherocytosis/Positive Osmotic Fragility Test?
        
        Autoimmune Haemolytic Anaemia/Hereditary Spherocytosis
        
        Direct Coomb Test?
        
        Positive- Autoimmune Haemolytic Anaemia
        
        Negative- Hereditary Spherocytosis
        
        Nope
        
        G6PD Deficiency
        
        Normal
        
        Fruits and Fegetables + Hypersegmented Neutrophils= Vitamin B12 (Pernicious Anaemia if associated autoimmune disease) (Fruits and vegetables have adequate Folic Acid)
        
        Beef and Bacon= Folic Acid (Beef and Bacon have adequate Vitamin B12)

This is so far, the best type of anemia chart for a medical student preparing for PLAB or even preparing for NEET PG after MBBS.

Pancytopenia- ALL, Lymphoma, Aplastic Anaemia
- ALL- Child, Pancytopenia, Blast cells on BM Biopsy
- Lymphoma- LNP Present (Reed-Sternberg Cells in Hodgkin/Irregular Small B Lymphocytes in Non-Hodgkin on BM Biopsy)
- Aplastic Anaemia- 2 out of 3- Hb<10, Platelets<50, Neutrophils<1.5
  - Bone Marrow Aspirate / Biopsy- Reduction in all hemopoietic tissues replaced by fat spaces

Overview: Types of Anemia Chart

Evaluation of Anemia requires brief history and physical examination. You can also read our post on anemia concepts including diagnosis, complications, and treatment. Following are some clues to understanding the types of anemia chart:

History

The clinical history may reveal most of the clues to diagnosis. One must ask the following questions to achieve maximum outcome:

Nutritional History
Family History
Geographical background
Pregnancy
Alcohol and Tobacco intake
Association of other symptoms- lymphadenopathy, splenomegaly, petechiae, etc.

Physical Examination

Of course, you have checked for pallor under the lower palpebral conjunctiva. But the following are signs you must also check while going through the types of anemia chart:

Forceful heartbeat
Strong peripheral pulses
Systolic flow murmur
Pale skin
Lighter palmar creases

Laboratory Tests

Once you have got the clue, you may proceed to laboratory investigation for diagnosis of anemia. Following is the list of tests you may want to get done before proceeding to the anemia algorithm:

Complete Blood Count (CBC)
Peripheral Blood Smear
Bone Marrow Examination
Iron Supply Studies

1. Complete Blood Count

Complete blood count or CBC is an essential step in approaching the types of chart and will involve the following:

A. Red blood cell count (RBC)

Hemoglobin
Hematocrit
Reticulocyte count

B. Red blood cell indices

Mean cell volume (MCV)
Mean cell hemoglobin (MCH)
Mean cell hemoglobin concentration (MCHC)
Red cell distribution width (RDW)

C. White blood cell count

Cell differential
Nuclear segmentation of neutrophils

D. Platelet count

E. Cell morphology

Cell size
Hemoglobin content
Anisocytosis
Poikilocytosis
Polychromasia

Check out our guide on the Basics of Reading Chest Xray.

2. Iron supply studies

Serum iron
Total iron-binding capacity
Serum ferritin

3. Marrow examination

A. Aspirate

M/E ratio
Cell morphology
Iron stain

B. Biopsy

Cellularity
Morphology

Approaching Types of Anemia Chart: Algorithm with CBC and Peripheral Blood Smear

Once the Complete blood count and peripheral blood smear test results in blood tests are up, you can follow the approach for anemia as given in this chart:

Anemia Clinical Approach Algorithm Flowchart Diagram

Mean Corpuscular Volume (MCV)

MCV is defined as the average volume of red blood cells. It is calculated as:

Mean Cell Volume (MCV) = (Hematocrit x 10) / Red Cell Count x 106)

The three conditions can come up with MCV:

MCV less than 80
MCV is between 80-100
MCV above 100

Implication for each value of Mean Corpuscular Volume:

MCV<80: Microcytic anemia- Small red blood cells
MCV 80-100: Normocytic anemia- Normal-sized red blood cells
MCV>80: Macrocytic anemia- Larger red blood cells than normal

For reference: Normal erythrocyte (RBC) volume in humans is 80 to 100 femtoliters (fL= 10⁻¹⁵ L)

Microcytic Anemia

Serum iron studies may reveal low iron and ferritin. However, TIBC (Total Iron Binding Capacity) differentiates between Iron deficiency anemia and Anemia of chronic disease. On the other hand, Mentzer Index is calculated to find if it is Thalassemia and further break down types of anemia chart.

Low Iron and Ferritin with High TIBC: Iron Deficiency Anemia

Low Iron and Ferrtin with Low TIBC: Anemia of Chronic Disease

Mentzer Index

The formula for Mentzer Index is as follows:

Mentzer Index = Mean corpuscular volume per red cell count

Mentzer Index = MCV/RBC

Interpretation of Mentzer Index

Index<13- less than 13 suggests a thalassemia trait
Index>13- more than 13 suggests that the patient has an Iron Deficiency or Anemia of Chronic Disease.

Normocytic Anemia

Reticulocyte count helps differentiate normocytic anemia into Hyper-proliferative and Hypo-proliferative. A normal reticulocyte count alone can help you rule out many other types of anemia in the chart.

Reticulocytes are immature red blood cells produced by Bone marrow. Reticulocyte actually predicts how fast red blood cells called reticulocytes are made by the bone marrow and released into the blood.

Normal range of Reticulocyte count: 0.5-1.5%

Hypo-proliferative: <2% Reticulocyte count

Seen in:

Leukemia
Aplastic anemia
Pure red cell aplasia

Hyper-proliferative: >2% Reticulocyte count