Hyperthyroidism

Keywords: Thyrotoxicosis

Causes

Appropriate Tests

 

Thyroid stimulating hormone.

If TSH is suppressed: Free T4 (thyroxine free).

If TSH is high or high normal, and there is a strong clinical suspicion of hyperthyroidism (ie, pituitary origin): Free T4 (thyroxine free).

If Free T4 (thyroxine free) is normal and there is a strong clinical suspicion of hyperthyroidism: Free T3 (triiodothyronine free).

See also Hyperthyroxinaemia

Radioactive isotope uptake studies (nuclear medicine).

Monitoring: TSH should be within the reference interval although this may take 2-3 months to achieve; Free T4 may be useful in the early stages of treatment.

Patients with a history of thyroid disease should always have TSH performed prior to anaesthesia/surgery.

See also Goitre.

Graves' disease

TSH receptor Ab are of limited value in monitoring treatment.

Toxic multinodular goitre

 

Toxic adenoma

 

Hashimoto disease

Thyroid peroxidase Ab (TPO antibodies), Thyroid Ab.

Subacute thyroiditis

TPO antibodies, Thyroid Ab.

Drug induced, especially

  • Amiodarone
  • Thyroxine
  • Interferon

 

Thyrotoxicosis factitia.

TSH overproduction, especially

  • Hypothalamic/pituitary tumour
  • Pituitary T4 resistance

 

See Pituitary hormone excess - thyrotrophin

Trophoblastic disease, including

  • Hydatidiform mole
  • Choriocarcinoma

Human chorionic gonadotrophin, beta subunit (Beta HCG quantitation).