Hypothyroidism. Randi Schutz. The Thyroid. Gland that regulates metabolism Located in the front of the neck just below the voice box (larynx) The thyroid gland releases two hormones: thyroxine (T4) and triioxdothyronine (T3)
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Hypothyroidism Randi Schutz
The Thyroid • Gland that regulates metabolism • Located in the front of the neck just below the voice box (larynx) • The thyroid gland releases two hormones: thyroxine (T4) and triioxdothyronine (T3) • The thyroid gland, as well as the pituitary gland and hypothalamus, control how much of these hormones are produced • There are three types of hypothyroidism: primary, secondary, and tertiary
Primary Hypothyroidism • Due to a defect in the gland, the thyroid cannot make enough T3 and T4 • The most common cause of primary hypothyroidism in the United States is the destruction of the thyroid gland by the immune system (Hashimoto’s thyroiditis) • Other causes of primary hypothyroidism include: • certain drugs such as lithium • radiation exposure to the neck • radioactive iodine used for treatment of hyperthyroidism • special x-ray dyes • surgical removal of part or all of the thyroid gland • some women develop after pregnancy (postpartum thyroiditis)
Secondary & Tertiary Hypothyroidism • In secondary hypothyroidism the thyroid gland produces too little hormone due to disorders of the pituitary gland (i.e. pituitary hypothyroidism) • Tertiary hypothyroidism is caused by disorders of the hypothalamus
Risk Factors • Age (older than 50) • Female gender • Obesity • Thyroid surgery • X-ray or radiation treatments to the neck
Early Symptoms • Cold intolerance • Constipation • Depression • Fatigue • Weakness • Muscle or joint pain • Paleness • Thin, brittle hair and fingernails • Dry, itchy skin • Weight gain and water retention
Late Symptoms • Decreased sense of taste and smell • Dry flaky skin • Hoarseness • Menstrual disorders • Puffy face, hands, and feet • Slow speech • Thickening of skin • Thinning of eyebrows
Exams and Tests • Physical examination may reveal: • Smaller than normal thyroid gland (but sometimes may also be normal in size or enlarged) • Coarse facial features • Firm swelling of arms and legs • Loss of the edges of eyebrows • Low blood pressure • Slow heart rate • Low temperature • Pale, yellow, and dry skin • Slow muscle relaxation when reflexes are tested • Thin, brittle hair • Chest x-ray may show enlarged heart
More Exams and Tests • Laboratory tests include: • High levels of thyroid stimulating hormone (TSH) indicate that the thyroid is not producing sufficient levels of thyroid hormone (mainly T4). TSH does not diagnose secondary and tertiary hypothyroidism. • Low free T3 and T4 • Total T3 and T4 • Anemia on a complete blood count • Increased cholesterol levels • Increased liver enzymes • Increased serum prolactin • Low serum sodium
Treatment • Treatment is to replace the thyroid hormone that is lacking • T4 is used most often, but a combination of T4 and T3 is also used • Receive the lowest dose that relieves symptoms and brings blood tests to a normal range • Periodic monitoring of TSH levels Requires life-long therapy, can be completely controlled with early treatment
Related Complications • Myxedema coma, the most severe from of hypothyroidism (rare) • Signs and symptoms include: low temperature, decreased breathing, low blood pressure, low blood sugar, and unresponsiveness • Depression • Heart disease • Increased risk for infection • Infertility • Miscarriage • Pituitary tumors • Complications from too much thyroid hormone replacement: • Atrial fibrillation • Osteoporosis • Symptoms of hyperthyroidism
References Holt, Elizabeth H. "Hypothyroidism - primary." Medline Plus N.p., 17 June 2008. Web. 4 Dec. 2009. <http://www.nlm.nih.gov/medlineplus/ency/article/000367.htm>. "Hypothyroidism." American Association of Clinical Endocrinologists N.p., 2006. Web. 4 Dec. 2009. <http://www.aace.com/pub/thyroidbrochures/pdfs/Hypothyroidism.pdf>. "Hypothyroidism." Wikipedia N.p., 21 Nov. 2009. Web. 3 Dec. 2009. <http://en.wikipedia.org/wiki/Hypothyroidism#cite_ref-nlm_6-0>. Simon, Harvey. "Hypothyroidism." University of Maryland Medical Center N.p., 21 May 2009. Web. 4 Dec. 2009. <http://www.umm.edu/patiented/articles/what_causes_hypothyroidism_000038_2.htm>.