Hyperthyroidism Flashcards
What is the most common cause of hyperthyroidism?
And why does it cause hyperthyroidism?
What other type of conditions is it associated with?
Graves’ disease
AI
Auto-antibody - thyroid stimulating immunoglobulin
AAB imitates TSH = growth of thyroid = more thyroid hormone produced
Other AI disorders
What are the primary causes of hyperthyroidism?
Graves’
Toxic nodular goitre - follicular cells generate lots of thyroid hormone due to mutated TSH receptor on it
Hyperfunctioning thyroid adenoma - benign growth on thyroid produces xs T3/T4
Neonatal hyperthyroidism - mother has Graves’ so thyroid stimulating Ig crosses placenta and causes baby to make too much thyroid hormone in response
Give 2 RF of Graves’
Female**
FH
What are the sx?
Weight loss and increased appetite Irritable + weak Sweating, tremor Diarrhoea Mental illness: anxiety to psychosis Heat intolerant Loss of libido Oligomenorrhoea
What are the signs?
Sweaty/warm palms Fine tremor Tachycardia ± AF Hair thinning Goitre - dysphagia + hoarse voice Proximal myopathy Gynaecomastia Brisk reflexes Urticaria/pruritus + thyroid acropachy + pretibial myxoedema
What eye manifestations might you see that is linked to Graves’ disease?
What affect can this have on the optic nerve?
Eye-lid retraction
Periorbital oedema
Proptosis
It can stretch the optic nerve
What 2 blood Ix do you do and what do you see?
TFTs:
Low TSH, high T3/T4
Antibody screen:
TSH receptor antibodies (Graves’)
- aka thyroid stimulating Ig AAB
TPO and Tg antibodies
What 2 imaging can you do?
Radioisotope uptake scan
USS - ?cancer
What is the mx?
BB (propanolol)
Lubricating eye drops
Antithyroid drugs** (carbimazole, propylthiouracil)
Radioactive iodine (never in preg, in relapsed graves’ or TNG)
Thyroidectomy
What caution should you take with antithyroid drug use?
Causes agranulocytosis + neutropenia
What doses should anti-thyroid drugs be given at?
Start 10-20mg daily and titrate based on TFT (monthly)
When should propylthiouracil be given and why?
Reserved for 1st TM of pregnancy
It acts faster than carbimazole
Is T3 or T4 more useful in detecting an abnormality?
T3
What is seen on TFTs in secondary hyperthyroidism?
High TSH, high T3/T4
