Raised in hyperthyroidism, often before the thyroxine level is elevated. Lowered in hypothyroidism and in any chronic illness. Of value when the concentration of thyroxine binding globulin is raised, as in pregnancy, or when taking the contraceptive pill or other oestrogens.

Patient Instructions:

This test is referred to an external laboratory

Sample Requirements:

Gold (SST)

Postal Samples: