Hypothyroidism



Hypothyroidism







  • Evaluation



    • General—state of decreased thyroid hormone with varied clinical manifestations


    • Clinical



      • Symptoms—tired, hypersomnia, dry skin, mild weight gain, constipation, cognitive slowing, and so on


      • Signs—bradycardia, slow speech, pallor, periorbital edema, delayed relaxation of reflexes, and so on


    • Etiology



      • Primary hypothyroidism (thyroid-stimulating hormone [TSH]) ↑, free T4 ↓)—disorder of the thyroid gland



        • Ninety-five percent of hypothyroidism in the United States is a result of primary thyroid failure, including the following:



          • Autoimmune thyroiditis (Hashimoto’s)


          • Ablation (surgical, radioiodine, radiation)



        • Other permanent causes



          • Congenital (1/3,500 live births in the United States)


          • Infiltrative disorders (e.g., hemochromatosis, amyloidosis, leukemia, etc.)


          • Iodine deficiency (not found in the United States, but found in third world regions)


        • Transient causes



          • Subacute thyroiditis (if viral—painful, if postpartum—painless)


          • Drug induced (amiodarone, lithium, interferon-α, etc.)


      • Secondary hypothyroidism (TSH ↓, free T4 ↓)—disorder of the hypothalamic-pituitary axis



        • Pituitary tumor


        • Sheehan’s syndrome


        • Cranial/pituitary radiation


        • Infiltrative disorders


      • Subclinical hypothyroidism (mild TSH ↑ [5-20 mIU/L], free T4 normal)



        • May progress to overt hypothyroidism.


    • Epidemology—8♀: 1♂; prevalence increases with age


    • Diagnostic algorithm

Tags:
Aug 28, 2016 | Posted by in PSYCHIATRY | Comments Off on Hypothyroidism

Full access? Get Clinical Tree
Get Clinical Tree app for offline access