Hypothyroidism: Diagnosis and Evidence-Based Treatment.

Hypothyroidism affects up to 5% of the global population. Incidence increases with age and is more common in women and individuals with prolonged estrogen exposure when compared with people who have not been exposed to estrogen. Symptoms can develop slowly and often mimic symptoms of other disorders, including menstrual cycle abnormalities. Understanding risk factors and common presenting symptoms is important in providing high-quality primary and reproductive care. Diagnosis relies on simple-to-obtain, fairly inexpensive testing of thyroid-stimulating hormone (TSH) levels and confirmation with levels of thyroxine. Management of hypothyroidism usually involves monotherapy with levothyroxine taken on an empty stomach. There are 2 methods for beginning levothyroxine treatment, and outpatient primary care clinicians can use shared decision-making to determine the best initiation method for each individual. Follow-up involves regular assessment of levels of TSH and symptom relief. Although some patients may need referral for specialist treatment, the majority of individuals with hypothyroidism can be diagnosed and treated by their outpatient primary care providers.