| Etiologies | Effective | % |
| Infectious | 13 | 31.0 |
| Inflammatory (neoplasia and autoimmune disease) | 13 | 31.0 |
| Chronic bleeding | 4 | 9.5 |
| Chronic kidney disease | 6 | 14.2 |
| Acute hemorrhage | 1 | 2.4 |
| Hemolysis | 1 | 2.4 |
| unexplained anemia | 4 | 9.5 |
| Total | 42 | 100.0 |