Common causes of hypothyroidism include:
- Thyroiditis (commonly Hashimoto’s thyroiditis)
- Iodine deficiency
- Thyroidectomy
- Radioiodine ablation
- Drug induced hypothyroidism
- Congenital hypothyroidism
Common causes of hypothyroidism include:

‡ The AACE, ATA and TES Consensus statement on subclinical thyroid dysfunction indicates that, in presence of TSH between 4.5 and 10 mlU/L and symptoms of hypothyroidism, the clinical judgement of the healthcare provider should be the key determining factor in considering treatment.
Patients being treated for hypothyroidism should have their serum TSH measured:2
If upper and lower normal TSH values are not available in the laboratory, the range of 0.45 to 4.12 mlU/L should be employed.