Hypothyroidism: Diagnosis and Treatment.

Clinical hypothyroidism affects one in 300 people in the United States, with a higher prevalence among female and older patients. Symptoms range from minimal to life-threatening (myxedema coma); more common symptoms include cold intolerance, fatigue, weight gain, dry skin, constipation, and voice changes. The signs and symptoms that suggest thyroid dysfunction are nonspecific and nondiagnostic, especially early in disease presentation; therefore, a diagnosis is based on blood levels of thyroid-stimulating hormone and free thyroxine.