| Decreased red cell production |
| Relative EPO deficiency |
| ID |
| Inflammation |
| Infection |
| Hyperparathyroidism |
| Nutritional deficiencies |
| Depletion of circulating red cell pool |
| Chronic blood loss, often occult |
| Reduced red cell circulating half-life |
| Frequent blood sampling |
| Decreased red cell production |
| Relative EPO deficiency |
| ID |
| Inflammation |
| Infection |
| Hyperparathyroidism |
| Nutritional deficiencies |
| Depletion of circulating red cell pool |
| Chronic blood loss, often occult |
| Reduced red cell circulating half-life |
| Frequent blood sampling |