26th April 2024

A 50-year-old woman presents with a 9-month history of increasing fatigue, weight gain, constipation, and feeling cold even in warm environments.

A 50-year-old woman presents with a 9-month history of increasing fatigue, weight gain, constipation, and feeling cold even in warm environments. She also reports a change in her voice, becoming hoarser, and difficulty in concentrating. Her family has noticed that her face appears puffier. On examination, her skin is dry, and there is mild, non-pitting oedema around her eyes. Her pulse is 58 bpm, and her reflexes are slowed.

Investigations:

Serum TSH: 14 mU/L (0.4–4.0)

Free T4: 8 pmol/L (12–22)

Serum cholesterol: Elevated

Complete blood count: Normal

Serum electrolytes: Normal

Which is the most likely cause of her presentation?