Detailed definition
Hypothyroidism is one of the most common endocrine conditions, affecting 5–10% of women over 50. Most cases in the US are autoimmune (Hashimoto thyroiditis) and progress gradually. Subclinical hypothyroidism (elevated TSH, normal free T4) is the most common presentation; overt hypothyroidism (elevated TSH, low free T4) is less common. Symptoms include fatigue, weight gain, cold intolerance, dry skin and hair, constipation, depression, cognitive slowing, menstrual irregularity, and elevated cholesterol. Treatment is daily oral levothyroxine titrated to keep TSH within an optimal range (typically 0.5–2.5 mIU/L for treated patients). Symptoms typically improve over weeks to a few months as TSH normalizes. Hypothyroidism is the most common imitator of menopausal symptoms — fatigue, weight gain, brain fog, mood — which is why TSH screening is part of any reasonable menopause workup.
Why it matters in menopause
A woman in her 50s with brain fog, fatigue, and weight gain may have low estrogen, low thyroid, or both. Treating only menopause when thyroid is also off underwhelms the patient. ClearedRx checks TSH at intake.