hypothyroidism /-thī″roidiz′əm/ [Gk, hypo + thyreos, shield, eidos, form] , a condition characterized by decreased activity of the thyroid gland. It may be caused by surgical removal of all or part of the gland, overdosage with antithyroid medication, decreased effect of thyroid-releasing hormone secreted by the hypothalamus, decreased secretion of thyroid-stimulating hormone by the pituitary gland, atrophy of the thyroid gland itself, or peripheral resistance to thyroid hormone. See also Hashimoto’s disease, myxedema. ▪ OBSERVATIONS: Manifestations include weight gain; cold, pale, dry, rough hands and feet; reduced attention span with memory impairment, slowed speech, and loss of initiative; swelling in extremities and around the eyes, eyelids, and face; menstrual irregularities; muscle aches and weakness; joint aches and stiffness; clumsiness; hyperstiff reflexes; decreased pulse; decreased blood pressure; agitation; depression; and paranoia. Hypothyroidism is diagnosed through lab testing. Serum and serum-free triiodothyronine and thyroxine (T3, T4) are decreased. Serum thyroid-stimulating hormone (TSH) is increased in primary hypothyroidism and decreased or normal in secondary hypothyroidism. Serum lipids and cholesterol levels are increased. Myxedema coma is a life-threatening complication of hypothyroidism that necessitates immediate treatment. It is preceded by gradual or sudden onset of mental sluggishness, drowsiness, and lethargy. Other complications include ischemic heart disease, congestive heart failure, pleural and pericardial effusion, deafness, psychosis, and anemia. ▪ INTERVENTIONS: The primary treatment for hypothyroidism is oral replacement of the thyroid hormone, with lifelong monitoring of TSH level at least annually. Triiodothyronine may be added to the replacement therapy regimen in patients who continue to have mood or memory problems. ▪ PATIENT CARE CONSIDERATIONS: Nursing care centers around education and includes instruction about signs and symptoms of hypothyroidism and hyperthyroidism, drug effects and side effects, and the need for thyroid hormone replacement therapy and monitoring for life. Nurses also play a role in early detection by advising patients to undergo thyroid screening every 2 to 3 years.
