Clinical Thyroid Disease

Question 1

What would thyroid function tests show in cases of primary, subclinical and secondary hypothyroidism?

Answer 1

Primary- raised TSH, low FT3 and FT4
Subclinical- raised TSH, normal FT3 and FT4
Secondary- low TSH, FT4 and FT3

Question 2

What are the causes of primary hypothyroidism?

Answer 2

Congenital 
Autoimmune thyroid disease (ie Hashimotos)
Iatrogenic 
Chronic iodine deficiency 
Post-subacute thyroiditis

Question 3

What are the causes of secondary hypothyroidism?

Answer 3

Pituitary/hypothalamic damage: 
Pituitary tumour 
Craniopharyngioma 
Post pituitary surgery or radiotherapy 
Sheehan's syndrome 
Isolated TRH deficiency

Question 4

What investigations are useful in hypothyroidism?

Answer 4

TSH/fT4

Autoantibodies