About the Thyroid Gland. The thyroid is a "butterfly-shaped" (1) endocrine gland located in the front of a your neck and above the collarbone. It produces hormones that help in the regulation of your metabolism, and as part of the endocrine system, it has an impact on all body systems.
Statistics about Thyroid Disease. The American Thyroid Association estimates that 20 million Americans have a form of thyroid disease, with more than half going undiagnosed. The Association states that "women are five to eight times more likely than men to have thyroid problems" and that "one woman in eight will develop a thyroid disorder during her lifetime" (2).
Symptoms of Low Thyroid Function. Many of the symptoms that indicate your thyroid may be functioning at sub-optimal levels are the kind that you might easily dismiss (3, 4). In addition, they can develop gradually over several years.
- Weight gain despite no change in dietary habits
- Lower body temperature or greater sensitivity to cold
- Fatigue, sluggishness, or feeling run down
- Dry skin and hair
- Muscle cramps or weakness
- Puffy face
- Hoarse voice
- Heavier menstrual flow in women
- Swelling in the front of the neck
- Higher levels of cholesterol, particularly LDL cholesterol.
About Hypothyroidism. In general, this occurs when they thyroid gland does not make enough thyroid hormones. The most common form of hypothyroidism is Hashimoto's thyroiditis, which is an autoimmune disease (3). In this case, the immune system mistakenly attacks the thyroid gland.
Thyroid Function Tests. The following laboratory tests are performed to evaluate thyroid function (3, 5):
- TSH: This test for Thyroid Stimulating Hormone is the first test that you may encounter to determine how well the thyroid is functioning. In the case of low thyroid function, this level will typically be higher than normal. However, the reference range is quite broad and a value on the higher end of normal may also indicate your thyroid is not functioning as well, especially if some of the symptoms above are present.
- T4: Also known as thyroxine, this is the major hormone secreted by the thyroid gland. The Free T4 test is better to evaluate how the thyroid is functioning because it is not bound to proteins and provides a more accurate picture of available levels in the blood. In someone with low thyroid function, this level is likely to be lower.
- T3: Also known as triiodothyronine, it results when an iodine atom is removed from T4 (which contains 4 of them). It is considered the most active form of thyroid hormone. This test may or may not be helpful when evaluating low thyroid function, as it may appear normal.
- Thyroid Antibody: It is useful to measure thyroid antibodies (most commonly thyroid peroxidase and thyroglobulin) in order to figure out the cause of thyroid problems, especially in the case of Hashimoto's.
- Celiac Disease. It is suggested that there is an increased prevalence of celiac disease among people with autoimmune conditions, such as thyroid disease (6,7,8).
- Anemia. Other research (9,10) indicates that symptoms consistent with anemia resulting from B12, iron, or folate deficiency may also be seen in people with low thyroid function.
- High Cholesterol. With low functioning thyroid, the body may not be able to process cholesterol as well, which results in an accumulation of total and LDL-cholesterol in the blood stream (11).
- Medline Plus. Thyroid Diseases. Accessed January 2014.
- American Thyroid Association. General Information/Press Room. Accessed January 2014.
- American Thyroid Association. FAQ: Hypothyroidism. Accessed January 2014.
- Office of Women's Health, US Department of Health and Human Services. Thyroid disease fact sheet. Accessed January 2014.
- American Thyroid Association. Thyroid Function Tests. Accessed January 2014.
- Chin, L, et al (2007). Celiac Disease and Autoimmune Thyroid Disease. Accessed January 2014.
- Murray, J. (1999). The Widening Spectrum of Celiac Disease. The American Society for Clinical Nutrition. Accessed January 2014.
- Saregna-Guidetti, C, et al (2001). Prevalence of Thyroid Disorders in Untreated Adult Celiac Patients and Effect of Gluten Withdrawal: an Italian Multicenter Study. American Journal of Gastroenterology. Accessed January 2014.
- Jabbar, A, et al. (2009). Vitamin B12 Deficiency Common in Primary Hypothyroidism. Accessed January 2014.
- Erdogan, M, et al. (2012). Characteristics of anemia in subclinical and overt hypothyroid patients. Endocrine Journal. Accessed January 2014.
- Rizos, CV, et al. (2011). Effects of Thyroid Dysfunction on Lipid Profile. The Open Cardiovascular Medicine Journal. Accessed January 2014.
Written by Michelle Baglio of Optimal Nutrition and Health (Google+). The information contained in this post is provided for educational purposes only with the understanding that Optimal Nutrition and Health makes no warranties, either expressed or implied, concerning the accuracy, completeness, reliability, or suitability of the information. Readers are advised not to use information in this post or others found on this website for the treatment or prevention of disease, and it should not be used in place of medical treatment or advice. Please do not reprint this post for distribution without my permission. To feature on your website or social media, please link to this post as the original source.