Iron Tests (Serum Iron, TIBC, UIBC)
Definition
A group of tests that evaluate iron status:
| Test | What it measures |
|---|---|
| Serum iron | The amount of iron in the blood |
| Transferrin | The protein that carries iron in the body |
| TIBC (Total Iron-Binding Capacity) | How well iron binds to transferrin and other proteins |
| UIBC (Unsaturated Iron-Binding Capacity) | The unused capacity of transferrin to bind iron |
| Ferritin | The amount of iron stored in the body (a separate entry, see above) |
Purpose
Detects low iron pointing to anemia. Distinguishes between types of anemia. Identifies excess iron (hemochromatosis). Measures iron storage in the liver. Evaluates restless leg syndrome or adult-onset Still's disease. Monitors treatment effectiveness.
Results
- Low iron, iron deficiency anemia, other types of anemia, or thalassemia
- High iron, hemochromatosis, lead poisoning, or liver disease
Normal Values
Laboratory-specific.
Risks and Limitations
Low iron may not cause symptoms until the level is very low. Certain medications, including birth control pills and estrogen therapies, affect iron levels. The menstrual cycle changes results.