A 42-year-old woman has noticed dry skin, fatigue, and weight gain over the past 3 months. Her blood pressure is 110/70 mm Hg, pulse 60/min, and heart and lungs are normal. Her skin feels rough and dry, but the rest of the examination is normal. Her biochemistry is normal but the thyroid-stimulating hormone (TSH) is 39 mU/L (0.5–5 mU/L). Which of the following is the most likely cause for her elevated TSH?
(A) trauma
(B) radioactive iodine ingestion
© primary hypothyroidism
(D) parathyroid surgery
(E) antithyroid chemicals
solution:
Primary hypothyroidism is the most common cause of hypothyroidism in adults. Primary hypothyroidism is several times more common in women than in men and occurs most often between the ages of 40 and 60. Postablative hypothyroidism (radiation or surgery induced) is also very common