How to work up anemia from the blood count
Other platforms explain it with text and video. In VMS you practice it on the patient.
Anemia is a sign, not a diagnosis. The red cell size and the reticulocyte count narrow down the cause quickly.
Step by step
Check for bleeding first
Ask about black stools, vomiting blood or heavy periods, and check vital signs. Fast bleeding needs urgent care before any workup. [1]
Confirm the anemia
Hemoglobin under about 13 g/dL in men or 12 g/dL in nonpregnant women is anemia. Compare with prior values. [2]
Sort by cell size (MCV)
Use the table below to group the anemia as small, normal or large cells. [2]
Check iron for small cells
Low ferritin confirms iron deficiency. In adult men and women after menopause, iron deficiency needs a GI bleeding workup. [2]
Check B12 and folate
Also think of alcohol, liver disease, low thyroid and drugs such as methotrexate. [2]
Check the reticulocyte count
High reticulocytes mean the marrow is responding to blood loss or hemolysis. Low reticulocytes mean the marrow is not making enough cells. [2]
Look at the other cell lines
Low white cells or platelets too suggests a marrow problem and needs a blood smear and specialist review. [2]
Common errors
- Giving iron without looking for the source of blood loss.
- Ignoring the reticulocyte count.
- Missing low white cells or platelets alongside the anemia.
Anemia by cell size (typical MCV 80 to 100 fL) [2]
| MCV | Group | Common causes |
|---|---|---|
| Under 80 fL | Small cells (microcytic) | Iron deficiency, thalassemia, chronic disease |
| 80 to 100 fL | Normal size (normocytic) | Acute blood loss, kidney disease, chronic disease, hemolysis |
| Over 100 fL | Large cells (macrocytic) | B12 or folate deficiency, alcohol, liver disease, drugs |
Practice it in VMS
In VMS you do this on the patient, not on paper: every step goes on the checklist with a score, and in Teach mode Blocky tells you what comes next.
VMS cases that train this skill
Sources
Facts and steps follow AAMC Core Entrustable Professional Activities (Core EPAs); NCCPA PANCE Content Blueprint. VMS is not affiliated with these organizations. Updated: 2026-10-11.