Hyperthyroidism Flashcards
What is hyperthyroidism?
Where there is over-production of thyroid hormone by the thyroid gland
What is thyrotoxocosis?
An abnormal and excessive quantity of thyroid hormone in the body
Describe primary hyperthyroidism
due to thyroid pathology
Describe secondary hyperthyroidism
the condition where the thyroid is processing excessive thyroid hormone as a result of overstimulation by TSH. This is from the pituitary or hypothalamus
Describe Grave’s disease
an autoimmune condition where TSH receptor antibodies cause a primary hyperthyroidism. . These are abnormal antibodies produced by the immune system that mimic TSH and stimulate the TSH receptors. This is the most common cause of thyroid disease
What is toxic multinodilar goitre also known as?
Plummer’s disease
Describetoxic multinodilar goitre
a condition where nodules develop on the thyroid gland that act independent;y of the normal feedback system and continuously produce excessive thyroid hormone
Describe exophthalmos?
the term used to describe bulging of the eyeball out of the socket caused by graves disease
This is due to inflammation and hypertrophy of the tissue behind the eyeball that pushes the eye forward
Describe pretibial myxoedema
a dermatological condition where there are deposits of mucin under the skin on the anterior aspect of the leg. This gives a discoloured, waxy oedematous appearance to the skin over this area.
It is specific to grave’s disease and is a reaction to TSH receptor antibodies
What are the universal features of hyperthyroidism?
anxiety and irritability sweating and heat intolerance tachycardia weight loss fatigue frequent loose stools sexual dysfunction
What features are unique to grave’s disease?
Diffuse goitre (without nodules)
Graves eye disease
bilateral exopthalmos
Pretibial myxoedema
What are the unique features of toxic multinodular goitre?
goitre with firm nodules
most patients over 50
second most common cause of thyrotoxicosis
Describe a solitary toxic thyroid nodule and its treatment
this is where a single abnormal thyroid nodule is acting alone to release thyroid hormone. these are normally benign adenomas. They are treated with surgical removal of the adenoma
Describe De Quervain’s thyroiditis
describes the presentation of a viral infection with fever, neck pain and tenderness, dysphagia and features of hyperthyroidism. There is a hyperthyroid phase followed by a hypothyroid phase as the TSH falls due to negative feedback.
What is the management if De Quervain’s thyroiditis?
IT is self limited and is treated with NSAIDs for pain and inflammation and beta blockers for symptomatic relief for hyperthyroidism
Describe a thyroid storm
A rare presentation of hyperthyroidism.
Also known as a thyrotoxic crisis.
Severe presentation with pyrexia, tachycardia and delirium.
Requires admission for monitoring and may need supportive care with fluids, anti-arrhythmic medications as well as beta-blockers
What is the first line anti-thyroid drug?
Carbimazole
What are the two strategies for carbimazole treatment?
Titration-block
block and replace
Why is carbimazole preferred to propylthiouracil?
it is used in a similar way to carbimazole but there is a small risk of severe hepatic reactions, including death
Describe radioactive iodine treatment
involves drinking a single dose or radioactive iodine
This is taken up by the thyroid gland and the emitted radiation destroys a proportion of the thyroid cells
This reduction in functioning cells results in a decrease of thyroid hormone production and this remission from hyperthyroidism. Remission can take 6 months and patients can be left hypothyroid afterwards and require levothyroxine replacement
What are the rules for radioactive iodine treatment?
The patient:
must not be pregnant and not allowed to get pregnant for 6 months
must avoid close contact with children and pregnant women for 3 weeks
limit contact with anyone for several days after receiving the dose
Describe beta-blockers in the management of hyperthyroidism
used to block the adrenalin related symptoms of hyperthyroidism propanolol is a good choice because it non-selectively blocks adrenergic activity (ie doesn’t just work on the heart)
do not treat the underlying problem but controls symptoms
Describe the surgery for hyperthyroidism
To surgically remove the whole thyroid or thyroid nodules.
This effectively stops the production of thyroid hormone, patients will require levothyroxine replacement for life
