Hypothyroidism — KFP-style written assessment

KFP 1 (10 marks)

A 38-year-old woman presents with fatigue, weight gain and cold intolerance. TSH is 8.5 mIU/L (ref 0.4–4.0); free T4 normal; anti-TPO antibodies positive. She wants to feel better. ^[4]

1. What is her biochemical diagnosis and what defines it? (2) ^[4]
2. Should she be treated? Justify with the threshold logic. (4) ^[4]
3. She starts levothyroxine 50 µg daily. When do you recheck TSH and what target applies? (2) ^[1]
4. She asks whether adding T3 would help her feel better faster. What does Cochrane evidence say? (2) ^[3]

Model answers

1. Subclinical hypothyroidism — raised TSH with normal free T4. ^[4]
2. Yes, treat: TSH 4–10 mIU/L with positive anti-TPO antibodies and clear symptoms justifies a trial of levothyroxine. Above 10 mIU/L treat outright; below 10, antibodies and symptoms tip the balance toward treating. ^[4]
3. Recheck TSH six to eight weeks after starting or any dose change; target sits within the laboratory reference range. ^[1]
4. Cochrane meta-analysis of 1216 patients across eleven trials found no difference in bodily pain, depression, anxiety, fatigue, quality of life, weight, cholesterol or lipids between T4/T3 combination and monotherapy. T4 monotherapy remains standard. ^[3]