Hyperthyroidism Flashcards
Briefly describe thyroid axis.
TRH > TSH > thyroxine
Thyroxine negatively feeds back to TRH AND TSH
If thyroid is destroyed by autoimmunity what are the levels of TSH and thyroxine?
thyroxine low
TSH high
Graves’ disease
Autoimmunity
Antibodies bind to + stimulates TSH receptor
Causes goitre (smooth) + hyperthyroidism
Define exophthlamos.
bulging of the eye anteriorly out of the orbit
Define pretibial myxoedema.
swelling (non pitting) on shins of patients wirh Graves’
Plummer’s disease
a condition where there is a single hyperfunctioning nodule producing excess thyroid hormone
Symptoms of hyperthyroidism
nervousness, anxiety and irritability. mood swings. difficulty sleeping. goitre persistenttirednessand weakness. sensitivity to heat tachycardia (palpitations)
thyroid storm
severe thyrotoxic crisis
Classes of drugs used to treat hyperthyroidism
thionamides
potassium iodide
radioiodine
beta blockers
examples of thionamides
carbimazole
propylthiouracil (PTU)
mechanism of action of thionamides
inhibition of thyroid peroxidase and hence T3/4 synthesis
side effects of thionamides
rashes
agranulocytosis (reduction of neutrophils)
mechanism of action of potassium iodide
blocks uptake of iodine into the thyroid
risks for thyroid surgery
risk of damage to left recurrent laryngeal nerve (voice change)
scar
aesthetic
can lose parathyroid glands
Viral (de Quervain’s) thyroiditis symptoms
pyrexia
painful dysphaghia
hyperthryoidism
swelling
