Diagnostic Blood Test:

Thyroxine Binding Globulin (TBG)

The thyroid gland makes hormones, which are transported through the bloodstream by proteins like thyroxine binding globulin (TBG). Abnormal TBG levels may be a sign of thyroid conditions that can lead to changes in energy levels, weight, or mood. TBG concentrations may also change due to liver or kidney problems.