Patients usually present with nonspecific symptoms of weakness, lethargy, depression, and mild weight gain.
Commonly, disease is subclinical.
Physical exam may show dry skin, thick tongue, eyelid edema, and bradycardia.
Elevated thyroid-stimulating hormone and low free thyroxine.
Treatment is levothyroxine at a starting dose of 1.6 micrograms/kg daily or 25 micrograms daily in older patients or those with coronary artery disease.
Over-treatment is uncommon but can lead to iatrogenic hyperthyroidism.
Hypothyroidism is a clinical state resulting from underproduction of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Most cases (95%) are due to primary hypothyroidism, a failure of the thyroid gland to produce thyroid hormones. The remaining 5% of cases are due to secondary hypothyroidism, underproduction of thyroid-stimulating hormone (TSH) by the pituitary gland. Subclinical hypothyroidism is a state of usually asymptomatic, mild thyroid failure, with normal levels of T4 and T3, and minimal elevation of TSH. Myxedema coma is a rare severe form of hypothyroidism with multiorgan failure.
History and exam
- cold sensitivity
- weight gain
- menstrual irregularity
- dry or coarse skin
- eyelid edema
- thick tongue
- facial edema
- coarse hair
- deep voice
- diastolic hypertension with or without narrow pulse pressure
- delayed relaxation of tendon reflexes
- iodine deficiency
- female sex
- middle age
- family history of autoimmune thyroiditis
- autoimmune disorders
- Graves disease
- postpartum thyroiditis
- Turner and Down syndromes
- type 1 diabetes
- primary pulmonary hypertension
- multiple sclerosis
- radiation therapy
- infiltrative disease
- iodine excess
- amiodarone use
- lithium use
- textile workers
Adjunct Clinical Professor
Department of Family Medicine
University of North Carolina
WM declares that he has no competing interests.
Professor of Medicine
Chair of Family Medicine
University of Chicago Medical Center
BE declares that he has no competing interests.
Queen Elizabeth Hospital
SR declares that he has no competing interests.
Caerphilly Miners' Hospital
LP declares that he has no competing interests.
University of Copenhagen
BN declares that she has no competing interests.
Professor of Internal Medicine
Endocrinology Division Chief
Texas Tech University Health Sciences Center - School of Medicine
JL declares that he has no competing interests.
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