Tonya Hopkins Medical Terminology II May 2012 Hypothyroidism Tonya Hopkins Medical Terminology II May 2012

Hypothyroidism ____________________________________ Hypothyroidism is a glandular disorder resulting from insufficient production of thyroid hormones.

Hypothyroidism Your thyroid is a small, butterfly-shaped gland located at the base of the front of your neck, just below your Adam's apple.

Hypothyroidism Thyroid Hormones: The thyroid gland produces two main hormones, thyroxine (T-4) and triiodothyronine (T-3). These hormones maintain the rate that the body uses fats and carbohydrates, control body temperature, influence heart rate, and help regulate the production of protein. The thyroid gland also produces calcitonin, which is a hormone that regulates the amount of calcium in the blood.

The rate at which T-4 and T-3 are released is controlled by the pituitary gland and the hypothalamus — an area at the base of your brain that acts as a thermostat for your whole system. The hypothalamus signals your pituitary gland to make thyroid-stimulating hormone (TSH). Your pituitary gland then releases TSH - the amount depends on how much T-4 and T-3 are in the blood. The thyroid gland regulates its production of hormones based on the amount of TSH it receives.

Causes of Hypothyroidism The most common cause is Hashimoto's disease (chronic thyroiditis). This disease causes the immune system to fail to recognize that the thyroid gland is part of the body's own tissue and attacks it like it were a foreign body (autoimmune). The attack by the immune system affects thyroid function and can destroy the gland. Other causes: Surgery – removal of the thyroid gland Viruses - Infections that depress thyroid hormone production can cause permanent hypothyroidism. Congenital Defect - Born without a properly functioning thyroid gland. Diet - An iodine-deficient diet can cause hypothyroidism. Radiation – Radioactive iodine to treat hyperthyroidism or radiation used for head or neck cancer can destroy the thyroid.

Symptoms of Hypothyroidism Goiter (Enlarged thyroid) Fatigue Weight gain Hoarse voice Muscle aches Heavy menstrual periods Brittle nails and hair Constipation Depression Pain or swelling in joints Pale, dry skin Premature gray hair

Tests & Treatments: Hypothyroidism A blood test is preformed to determine the level of TSH and T4. A low level of T4 and high level of TSH indicate an underactive thyroid. Physical Examination Nuclear Medicine Scan - Radioactive iodine tracer to see how well the thyroid gland is working. (After taking a radioactive iodine pill) Thyroid ultrasound – Most often used to evaluate a small nodule (lump) found during physical examination. Once diagnosed standard treatment is daily dose of a synthetic thyroid hormone. The most common type of medication used is Levothyroxine. The need for the medication is life-long in most cases.

Other Facts Higher risk if you are a woman over 50 There is no cure Increased risk of heart disease Women with untreated thyroid disease may have a higher risk of having a child with a birth defect