An overactive thyroid means that too much thyroid hormone is produced. The same three hormone groups will be reviewed:
In addition, other tests may be conducted, such as a thyroid nodule ultrasound to learn if there are nodules in the thyroid which may be causing issues due to their size or other indications; if that is the case, a needle biopsy may be ordered. An iodine thyroid scan may be ordered to understand if the entire gland or a specific nodule is the root cause of the hyperthyroidism.
Thyroid hormone excess may result from a variety of medical conditions. However, the autoimmune disease, Graves’ disease, accounts for 60 to 80 percent of cases. Graves diseases affects up to 2 percent of women. It typically appears between the ages of 20 and 50, however the risk of developing Graves’ disease increases three-fold during the post-partum period.
Reducing the amount of thyroid tissue with radioiodine (131I) treatment usually represents the first line of treatment for thyroid hormone excess in the United States. Before you can undergo radioiodine treatment, your doctor will commonly prescribe a one-month course of anti-thyroid medication. This pre-treatment reduces the risk that your thyroid gland will release toxic amounts of stored thyroid hormone after you receive radioiodine. You will also need to observe radiation safety precautions for several days after radioiodine treatment. These precautions, which usually include avoiding close contact with children and pregnant women, vary from area to area. Your doctor will review these precautions with you before you schedule the treatment, so you can plan ahead. You may develop mild pain in the area of your thyroid gland 1 to 2 weeks after treatment, however this is rare and usually managed with over-the-counter pain medication, such as acetaminophen. Some patient require a second treatment with radioiodine. You will know if you need a second treatment approximately 6 months after the first. Almost all patients who undergo radioidodine treatment still require medication to manage their symptoms.
Medical treatment for thyroid hormone excess involves one of three drugs: methimazole, carbimazole, and propylthiouracil. All of these drugs target the same enzyme, thyroid peroxidase, which converts iodine into active thyroid hormone. Your doctor will usually start you on 10 to 20 mg of methimazole or carbimazole by mouth, two or three times per day. Once your symptoms resolve, your doctor will reduce this to a once daily dose, but that takes time – a minimum of 3 to 4 weeks and usually 6 to 8 weeks. If you are pregnant or nursing, carbimazole and methimazole can cause serious thyroid problems for your baby. In those cases, your doctor will switch you to a propylthiouracil, typically in a dose of 100 to 200 mg every three or four times per day for the duration of treatment. As with all medications, you should follow your doctor’s instructions and read the package insert that comes with your prescription.
Subtotal or near-total thyroidectomy is a surgical procedure for patients who do not tolerate medications and are not candidates for radioiodine therapy. As with radioiodine therapy, your doctor will prescribe pretreatment with anti-thyroid drugs, as well as potassium iodide prior to surgery. Complications of surgery include bleeding, swelling of the larynx, hyperparathyroidism, but these are uncommon with surgeons who regularly perform thyroidectomy. When you select a surgeon, ask how many thyroidectomies she has performed in the last year and over the course of her career. Ideally, you should select a surgeon who has performed at least three in the past year and many more over the course of her career.
Most patients in the United States are managed with a combination of radioiodine treatment and medications. Autoimmune thyroid disease is an evolving condition and so, too, is treatment! Changing treatment reflects the nature of the disease, not a failure on the part of your doctor, so be prepared. Your doctor will follow your response to treatment by regularly monitoring your thyroid hormone levels. She may order blood tests every few months initially, to every year or so in a patient who has been stable for many years.
About the Author
Heather Breen is a physician and registered dietitian living in Charlotte, North Carolina.
This blog post was originally published by AutoimmuneMom.com, written by Heather Breen, and first published on Apr 2, 2012.