Hypothyroidism Flashcards
What is the most common cause of hypothyroidism?
Hashimoto’s thyroiditis
What is primary hypothyroidism?
The thyroid produced inadequate thyroid hormones
- Negative feedback is absent, resulting in increased production of TSH
What TFTs would be seen in primary hypothyroidism?
Low T3/T4
High TSH
What is secondary hypothyroidism?
The pituitary behaves abnormally and produces inadequate TSH, resulting in under stimulation of the thyroid
What TFTs are seen in secondary hypothyroidism?
Low TSH
Low T3/T4
What are the other causes of hypothyroidism?
Iodine deficiency
Treatment for hyperthyroidim
Lithium
Amiodarone
What are the clinical features of hypothyroidism?
Weight gain
Cold intolerance
Lethargy
Dry skin
Constipation
Menorrhagia
Coarse hair and hair loss
Fluid retention
Bradycardia
Goitre
What are the causes of secondary hypothyroidism?
Pituitary adenoma
Surgery to the pituitary
Radiotherapy
Sheehan’s syndrome
Trauma
What are the primary investigations used to diagnose hypothyroidism?
TFTs
Antibodies - anti-TPO associated with Hashimoto’s thyroiditis
Inflammatory markers - raised in Dequervain’s thyroiditis
What is the management of primary hypothyroidism?
Levothyroxine
- Offer with regular review of symptoms
- TSH every 3 months
What are the complications of hypothyroidism?
Cardiovascular disease
Carpal tunnel syndrome
Peripheral neuropathy
Myxoedema coma
Thyroid lymphoma
What are the side effects of thyroxine?
Hyperthyroidism
AF
Osteoporosis
Angina
What TFTs would be seen in subclinical hypothyroidism?
High TSH
Normal T3/T4
When should subclinical hypothyroidism be treated?
If the TSH level is >10 on 2 separate occasions, 3 months apart
