What Are the Causes of Fluctuating Thyroid Levels?
Abnormally high thyroid hormone levels, or hyperthyroidism, can cause increased heart rate, anxiety and weight loss. When thyroid hormone levels drop too low the result is fatigue, weight gain and slowed heart rate, a condition known as hypothyroidism.
Inflammation of the thyroid gland can disrupt normal thyroid hormone levels in numerous ways. Hashimoto’s thyroiditis is an autoimmune disorder, and one of several diseases that causes inflammation of the thyroid 3. Hereditary factors, gender, radiation exposure and pregnancy all influence a person’s likelihood of getting Hashimoto’s thyroiditis, according to the U.S. Department of Health and Human Services. This disease is the most common cause of hypothyroidism.
Toxic substances and radiation exposure can also inflame the thyroid gland, prompting an abnormal increase in the release of stored of thyroid hormones.
Postpartum thyroiditis typically affects less than 10 percent of women during the year after giving birth, according the Hormone Foundation. It begins with a 2- to 4-month phase during which the thyroid is overactive. The over-stimulation eventually damages the gland, which then produces less hormone, beginning a hypothyroid phase.
- Inflammation of the thyroid gland can disrupt normal thyroid hormone levels in numerous ways.
- Toxic substances and radiation exposure can also inflame the thyroid gland, prompting an abnormal increase in the release of stored of thyroid hormones.
What Is Low TSH?
Tumors of the pituitary gland can affect thyroid hormone levels. The pituitary gland produces thyroid stimulating hormone, or TSH. Some pituitary tumors cause an increase in the production of thyroid stimulating hormone, while others can cause decreases. Thyroid stimulating hormone in turn prompts the thyroid to produce greater amounts of hormone.
According to Lab Tests Online, dysfunction of the hypothalamus can alter the pituitary gland’s ability to make TSH, which in turn affects thyroid hormone levels 2. Benign tumors called adenomas can grow in the thyroid and produce excess thyroid hormone even in the absence of the TSH usually released by the pituitary gland. The Hormone Foundation states that 90 percent of thyroid tumors are benign, but cancerous thyroid nodules do exist, and can spread through the body rapidly.
- Tumors of the pituitary gland can affect thyroid hormone levels.
- Some pituitary tumors cause an increase in the production of thyroid stimulating hormone, while others can cause decreases.
A deficiency or excess of iodine in the diet can affect the function of the thyroid gland. Iodine is essential for the creation of thyroid hormones. In the United States, iodine is added to salt, which has lead to an elimination of iodine deficiency from the realm of major public health problems, but in some other areas of the world, iodine deficiency still causes problems such as:
What Is Low TSH?
Side Effects of Hypothyroidism
What Is Considered a Low TSH Level?
Iodine & Selenium Dosage for Thyroid Problems
What Does Low TSH Level Mean?
Can I Eat Seaweed If I Have Hyperthyroidism?
Symptoms of High TSH Levels
Gout and Iodine
L-Carnitine & Hypothyroidism
What Does a High TSH Level Mean?
- MyThyroid.com: Iodine
- Lab Tests Online: Pituitary Disorders
- MedlinePlus: Thyroid Diseases
- American Thyroid Association. General Information/Press Room.
- Pirahanchi Y, Jialal I. Physiology, Thyroid Stimulating Hormone (TSH). In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Updated April 25, 2019.
- AACC. Hashimoto Thyroiditis. Lab Tests Online. Updated October 18, 2019.
- DeGroot LJ. Graves’ Disease and the Manifestations of Thyrotoxicosis. [Updated 2015 Jul 11]. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2015.
- Nguyen QT, Lee EJ, Huang MG, Park YI, Khullar A, Plodkowski RA. Diagnosis and treatment of patients with thyroid cancer. Am Health Drug Benefits. 2015;8(1):30-40.
- Bindra A, Braunstein GD. Thyroiditis. Am Fam Physician. 2006;73(10):1769-76.
- Medeiros-Neto G. Multinodular Goiter. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Updated September 26, 2016.
- The National Institute of Diabetes and Digestive and Kidney Diseases. Hypothyroidism (Underactive Thyroid). Published August 2016.
- The National Institute of Diabetes and Digestive and Kidney Diseases. Hyperthyroidism (Overactive Thyroid). Published August 2016.
- Brent GA. Environmental exposures and autoimmune thyroid disease. Thyroid. 2010;20(7):755-61. doi:10.1089/thy.2010.1636
- Mcaninch EA, Bianco AC. The history and future of treatment of hypothyroidism. Ann Intern Med. 2016;164(1):50-6. doi:10.7326/M15-1799
- The National Institute of Diabetes and Digestive and Kidney Diseases. Grave’s Disease. Published September 2017.
- Stagnaro-Green, A., Abalovich, M, Alexander, E. et. al. Guidelines of the American thyroid association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid. 2011(21)10. doi:10.1089/thy.2011.0087
- Liu G, Liang L, Bray GA, et al. Thyroid hormones and changes in body weight and metabolic parameters in response to weight loss diets: the POUNDS LOST trial. Int J Obes (Lond). 2017;41(6):878-886. doi:10.1038/ijo.2017.28
- Bahn R, Burch H, Cooper D, et al. Hyperthyroidism and other causes of thyrotoxicosis: Management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists. Endocrine Practice. 2011;17(3). doi:10.1089/thy.2010.0417
- Braverman L, Cooper D. Werner & Ingbar's The Thyroid, 10th Edition. WLL/Wolters Kluwer; 2012.
- Garber J, Cobin R, Gharib H, et. al. Clinical practice guidelines for hypothyroidism in adults: Cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Endocrine Practice. 2012;18(6). doi:10.1089/thy.2012.0205
- Haugen A, Alexander K., Bible K, et. al. 2015 American Thyroid Association Management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer. Thyroid. 2016;26(1):1-133. doi:10.1089/thy.2015.0020
- Smallridge R, Ain K, Asa S, et. al. American Thyroid Association guidelines for management of patients with anaplastic thyroid cancer. Thyroid. 2012;22(11). doi:10.1089/thy.2012.0302
- Wells, S, Asa S, Dralle H, et. al. Revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma. Thyroid. 2015;25(6). doi:10.1089/thy.2014.0335
For 15 years, Charis Grey's award-winning work has appeared in film, television, newspapers, magazines and on the Internet. She has worked as a story editor on the CBS drama "Flashpoint" and her work appears bimonthly in "The Driver Magazine." She has a Bachelor of Science in biology and a doctorate in chiropractic medicine from Palmer College.