Thyroid

What is the thyroid? The thyroid gland, also known as the thyroid, is a small organ located in the front of the neck. The thyroid is wrapped around the windpipe (trachea), and is shaped similarly to a butterfly; small in the middle with two wide ‘wings’ that extend around the side of your throat. A diagram of the thyroid can be seen below. What does the thyroid do? According to the Healthline, glands are “important organs located throughout the body. They produce and release substances that perform certain functions” (1). The thyroid is an endocrine gland, meaning it produces hormones, and the hormones that are produced by the thyroid affect essentially every part of your body. Thyroid hormones regulate your metabolism, heart, and digestive function, and they also play a role in your brain and nerve development, muscle control, and mood. The hormones that your thyroid produces are called T3 (Triiodothyronine) and T4 (Thyroxine). Once T4 is released into the bloodstream, T4 travels to organs like the liver and kidneys where it is converted to its active form of T3. Thyroid conditions are very common. An estimated 20 million Americans currently are living with a thyroid condition, and up to 12% of Americans will develop a thyroid condition some time in their life. Did you know that women are 5-8 times more likely to develop a thyroid condition than men? 1 in 8 women will have a thyroid condition in her lifetime. Although the exact causes for many thyroid conditions are unknown, chronic thyroid conditions can be easily managed with the right medical attention. Thyroid cancers are caused by thyroid cells growing out of control. The thyroid gland makes 2 main types of cells; C cells (additionally called parafollicular cells) make calcitonin, a hormone that helps regulate how the body utilizes calcium, and follicular cells which use iodine from the blood to make thyroid hormones to regulate a person’s metabolism. There are three main types of known thyroid cancers: Papillary cancer (also called papillary carcinomas or papillary adenocarcinomas). An estimated 8 out of 10 thyroid cancers are papillary cancers. Papillary cancer tends to grow very slowly and usually develops in only one lobe of the thyroid gland. However, despite growing slowly, papillary cancers often spread to the lymph nodes in the neck. Even when these cancers have spread to the lymph nodes, they can often be treated successfully and are rarely fatal. Follicular cancer (also called follicular carcinoma or follicular adenocarcinoma). The next most common type of thyroid cancer is follicular cancer. Follicular cancer is more common in countries and places around the world where people have less iodine in their diet. These cancers don’t usually spread to lymph nodes, but they sometimes spread to other parts of the body, such as the lungs or bones. The prognosis (outlook) for follicular cancer is not as good as papillary cancer, but it still has a good outcome in most cases. Hürthle (Hurthle) cell cancer (also called oxyphil cell carcinoma). About 3% of thyroid cancers are this type, but it is much harder to find and to treat. Furthermore, most patients that have Hurthle cell thyroid cancer will not know their diagnosis until after the surgical removal of their thyroid nodule which was initially called a Hurthle cell tumor. In fact, most patients and even thyroid specialists have had very little to no experience with Hurthle cell thyroid cancer. According to the Clayman Thyroid Center, “Hurthle cell cancer typically starts within the thyroid as growth, or bump (nodule) in the thyroid that grows out of the otherwise normal thyroid tissue.” (3). Hypothyroidism is when your thyroid is underactive; it doesn’t make enough hormones to meet your body’s needs. Although most cases are mild, 4.6% of the US population ages 12 and older has hypothyroidism. Hypothyroidism has many symptoms that can vary from person to person, but common symptoms of hypothyroidism include fatigue, weight gain, a puffy face, trouble, tolerating cold, joint and muscle pain, constipation, dry skin, dry, thinning hair, heavy or irregular menstrual periods, fertility problems, depression, goiters and a slowed heart rate. The standard treatment for hypothyroidism is the synthetic thyroid hormone Levothyroxine to restore adequate hormone levels. Hyperthyroidism is when your thyroid is overactive; when your thyroid makes too much thyroid hormones for your body to handle. A little over 1.2% of the US population have hyperthyroidism, which is just over every 1 in 100 people. Similar to hypothyroidism, women are 2-10 times more likely than men to develop hyperthyroidism. Although symptoms will vary from person to person, symptoms of hyperthyroidism include nervousness or irritability, fatigue or muscle weakness, trouble tolerating heat, trouble sleeping, shaky hands, rapid and irregular heartbeat, frequent bowel movements or diarrhea, weight loss, mood swings and goiters. Goiters describe any enlargement of the thyroid gland. Goiters are relatively common, with around 5% of the US population having one. Goiters are not dangerous on their own, but they can be a symptom of thyroid cancers, hypo/hyperthyroidism, or something like pregnancy. Symptoms of a goiter can include a feeling of neck fullness or tightness, difficulty swallowing, difficulty breathing, coughing, and changes in your voice. When goiters are large enough they may appear as swelling in the neck. Grave’s disease is an autoimmune disease that causes damage to the thyroid gland. A thyroid gland affected by Grave’s disease produces too much thyroid hormones, making Graves' disease the most common cause of hyperthyroidism. Grave’s disease causes the body to make an antibody that attacks the cells of the thyroid gland, and the thyroid gland produces too many hormones to overcompensate. Unlike its name suggests, Grave’s disease has several forms of treatment that can help manage it and the likely resulting hyperthyroidism. Three examples of treatments include Antithyroid medicine, which is used to keep the thyroid gland from making too much thyroid hormone, radioactive iodine, to destroy thyroid cells so it cannot produce as much hormone, and surgery to remove all or most of the thyroid. However, Grave’s disease is not without complications/effects; untreated Grave’s disease can lead to problems during pregnancy, heart problems like irregular heartbeat (arrhythmia) heart failure, and in rare cases a thyroid storm. Thyroiditis is a general term that refers to inflammation of the thyroid gland. According to the American Thyroid Association, “Thyroiditis includes a group of individual disorders causing [thyroid] inflammation but presenting in different ways.” (1). The most common example of thyroiditis would be Hashimoto’s thyroiditis, which is the most common cause of hypothyroidism in the US. A second example would be postpartum thyroiditis, which causes temporary high thyroid hormone levels in the blood (thyrotoxicosis). Finally, subacute thyroiditis is the major cause of pain in the thyroid. Thyroiditis can also be a result of a patient taking the drugs interferon and amiodarone. What happens if someone doesn’t have a thyroid or has it removed? Someone who has their thyroid partially or fully removed may develop symptoms of an underactive thyroid (hypothyroidism). Most people with parts or all of their thyroid removed will end up taking the treatments for hypothyroidism since many of the results of the lack of thyroid are very similar to what hypothyroidism causes. However, treatment is often taken on a case by case basis and depends on both the patient’s and doctor’s decision. Sources: https://my.clevelandclinic.org/health/diseases/8541-thyroid-disease https://www.healthline.com/health/what-are-glands#glands-to-know https://www.restartmed.com/what-does-your-thyroid-do/ https://vsearch.nlm.nih.gov/vivisimo/cgi-bin/query-meta?v%3Aproject=medlineplus&v%3Asources=medlineplus-bundle&query=what+does+Triiodothyronine+do https://www.yourhormones.info/hormones/triiodothyronine/ https://medlineplus.gov/lab-tests/triiodothyronine-t3-tests/ https://www.hormone.org/your-health-and-hormones/glands-and-hormones-a-to-z/hormones/thyroxine https://www.endocrineweb.com/conditions/thyroid/all https://www.niddk.nih.gov https://www.mayoclinic.org/diseases-conditions/hypothyroidism/diagnosis-treatment/drc-20350289 https://www.thyroid.org/media-main/press-room/ https://apastyle.apa.org/style-grammar-guidelines/capitalization/diseases-disorders-therapies https://www.hopkinsmedicine.org/health/conditions-and-diseases/goiter https://www.womenshealth.gov/a-z-topics/graves-disease https://www.thyroid.org/thyroiditis/ https://www.cancer.org/cancer/thyroid-cancer/about/what-is-thyroid-cancer.html https://www.thyroidcancer.com/thyroid-cancer/hurthle