Hyperthyroidism Flashcards
what is hyperthyroidism
- thyrotoxicosis
- excessive production of thyroid hormone
- overactivity of thyroid gland resulting in elevated level of thyroid hormone circulating in body
describe the types of hyperthyroidism
primary:
- due to problem w/ thyroid itself
secondary:
- due to overstimulation by TSH
tertiary:
- due to overstimulation by TRH
what are some of the presentations of hyperthyroidism
generalised hyper metabolism
- goitre (moves on swallowing)
- diarrhoea
- weight loss, ↑appetite
- tachycardia, palpitations 2° to A.fib
- sweating, heat intolerability
- anxiety/irritability
- exophthalmos (Graves’)
- lid lag
- tremor
give some causes of hyperthyroidism
- Graves’ disease
- toxic multinodular goitre
- solitary toxic thyroid nodule
- De Quervain’s Thyroiditis
what is an emergency presentation/complication of hyperthyroidism
Thyroid storm or thyrotoxic crisis
describe Graves’ disease
- most common cause
- autoimmune
- -> TSH Ab stim thyroid TSH receptors
signs specific Grave’s
- diffuse goitre w/o nodules
- exophthalmos
- pretibial myxoedema
what is the most common cause of hyperthyroidism
Graves’ disease
describe toxic multinodular goitre
- 2nd most common cause
- more common in women and ↑age
- usually treated w/ radioactive iodine
describe solitary toxic thyroid nodule
usually benign adenoma
describe De Quervain’s Thyroiditis
- transient hyperthyroidism that develops after viral infection
- painful goitre
- period of hypothyroidism may follow
outline a thyroid storm
- rare medical emergency
- can progress from undiagnosed/untreated hyperthyroidism
- often presents w/ hyperthermia and/or thyrotoxic symptoms; tachycardia, hyperpyrexia, A.fib, nausea/vomiting/diarrhoea
assc w/ precipitating cause:
- withdrawal of antithyroid meds
- radio-iodine therapy
- surgery
what is the treatment for thyroid storm
- adequate hydration and cooling
- beta blockers e.g. propranolol
- administer antithyroid agent e.g propylthiouracil
- iodine (lugol solution) 4hrs after antithyroid treatment
what are some investigations for suspected hyperthyroidism
TFTs:
- primary; ↑T3/T4, ↓TSH, ↓TRH
- secondary; ↑T3/T4, ↑TSH, ↓TRH
- tertiary; ↑T3/T4, ↑TSH, ↑TRH
- USS of nodules
- fine needle aspiration of solitary nodules to exclude malignancy
- thyroid scintigraphy
what is the management of hyperthyroidism
- first line: carbimazole
- alternatively: propylthiouracil
- radioactive iodine
- -> single dose emits radiation and destroys thyroid cells
- surgery
- -> requires lifelong levothyroxine
