Health Encyclopedia

Thyroid Hormone Replacement Therapy

What is thyroid hormone replacement therapy?

Thyroid hormone therapy is the use of manmade thyroid hormones to raise abnormally low levels of natural thyroid hormones in the body. Thyroid hormone is usually given in pill form and is often used to treat an underactive thyroid that is secreting little or no thyroid hormones. The most commonly prescribed thyroid hormone replacement is pure synthetic thyroxine (T4).

Who needs thyroid hormone replacement therapy?

Thyroid hormone therapy is generally prescribed when a person's thyroid is not making enough thyroid hormone naturally (a condition referred to as hypothyroidism). Other reasons for using thyroid hormone therapy may rarely include:

  • To control the growth of the enlarged thyroid gland (also called goiter)

  • To control the growth of nodules on the thyroid gland

  • Treatment after the removal of the thyroid for benign or malignant disease

  • After treatment of hyperthyroidism by radioactive iodine ablation

How is thyroid hormone replacement therapy dosage determined?

Doctor's do careful blood testing to find the proper dose of hormone replacement therapy for each person. The blood tests reveal levels of thyroid hormones in the blood, as well as thyroid-stimulating hormone (TSH) released by the pituitary gland. The pituitary gland plays an integral role in the functioning of the thyroid gland. It controls how much thyroid hormone is released by producing TSH that "stimulates" the thyroid. Increased levels of TSH may indicate an underactive thyroid.

Yearly checkups are usually done to measure levels of thyroid hormones and TSH. Hypothyroidism can be a progressive disease, requiring dosage increases over time.

 

To ensure your thyroid hormone replacement works properly, consider the following recommendations:

  • Maintain regular visits to your doctor.

  • Take your thyroid medication daily on an empty stomach at the same time each day.

  • Tell your health care provider of your thyroid hormone treatment before beginning treatment for any other disease, as some adjunctive treatments can affect the dosage of thyroid hormone therapy.

  • Let your doctor know if you become pregnant.

  • Tell your doctor of any new symptoms that may arise.

  • Tell all health care providers of your thyroid condition and medication dosage.



Medical Reviewers:

  • MMI board-certified, academically affiliated clinician
  • Turley, Ray, BSN, MSN