Five Levels
Normal does not always mean good.
A reference range shows the central 95% of a healthy group; it is not an ideal target. Celtt summarizes where a value sits inside it with 5 levels.
Reference rangeStatistic: ~95% of healthy people fall within it.
Celtt levelBy position in the range: Very poor, Poor, Normal, Good, Very good.
| Level | TSH (0.4–4.0 mIU/L) |
|---|---|
| Very good | 1.3–3.1 |
| Good | 0.76–1.3 and 3.1–3.64 |
| Normal | 0.4–0.76 and 3.64–4.0 |
| Poor | 4.0–4.9 (and below 0.4) |
| Very poor | Above 4.9; deviation at 5.2: (5.2 − 4.0) / 1.8 = 66.7% |
- CLSI C28-A3 — reference interval principles
General information only; not diagnosis or treatment. Review your results with your clinician.
