| Biochemical criteria | Clinical picture |
---|
| TSH concentration | Thyroid hormone concentrations | |
Disorders of thyroid origin |
Subclinical hyperthyroidism | Below reference range | FT4 and FT3 within reference range | Symptomless or mild hyperthyroidism |
Hyperthyroidism | Below reference range | FT4 and/or FT3 increased | Hyperthyroidism |
Subclinical hypothyroidism | Above reference range | FT4 within reference range | Symptomless or mild hypothyroidism |
Hypothyroidism | Above reference range | FT4 below reference range | Hypothyroidism |
Secondary disorders |
Central hyperthyroidism | Within or above reference range | FT4 and/or FT3 increased | Hyperthyroidism |
Central hypothyroidism | Within or slightly below reference range | FT4 below reference range | Hypothyroidism |