20th August 2020

A 33-year-old woman was referred to her endocrinologist with symptoms of low mood, fatigue and poor concentration

A 33-year-old woman was referred to her endocrinologist with symptoms of low mood, fatigue and poor concentration. She mentioned feeling very cold despite it being a warm sunny day outside. She also mentioned that her sister is on a special diet due to gluten intolerance and her mother suffers from lupus. The endocrinologist organised a set of blood tests which are shown:

T₄  30mmol/L, TSH 7.1 mu/L, Na⁺ 128 mmol/L, K⁺ 3.9 mmol/L, Anti-thyroid peroxidase antibodies – positive

For the patient above, please select the SINGLE most likely diagnosis based on the clinical history and/or biochemical tests provided. Select ONE option from the list above. 

You may use the following reference ranges:

• Serum total thyroxine, T₄: 70 – 140 mmol/L
• Serum Thyroid stimulating hormone, TSH: 0.5 – 5.7mu/L
• Serum sodium, Na⁺: 135 – 145mmol/L
• Serum potassium, K⁺: 3.5 – 5.0 mmol/L
• Serum total calcium, Ca²⁺: 2.12 – 2.65 mmol/L
• Serum parathyroid hormone, PTH: 2 – 7 pmol/L
• Serum (fasting) glucose: 4 – 6 mmol/L