Hyperthyroidism/Thyrotoxicosis

Question 1

what is hyperthyroidism

Answer 1

refers specifically to conditions in which overactivity of the thyroid gland leads to thyrotoxicosis

Question 2

what is thyrotoxicosis

Answer 2

the clinical, physiological and biochemical state arising when the tissues are exposed to excess thyroid hormone

Question 3

what cardiac signs/symptoms are associated with thyrotoxicosis

Answer 3

palpitation, AF, cardiac failure(very rare)

Question 4

what sympathetic and CNS signs/symptoms are associated with thyrotoxicosis

Answer 4

sympathetic = sweating, tremor
CNS = anxiety, nervousness, irritability, sleep disturbance

Question 5

what GI signs/symptoms are associated with thyrotoxicosis

Answer 5

frequent and loose bowel movements

Question 6

what vision signs/symptoms are associated with thyrotoxicosis

Answer 6

lid retraction(not specific to Graves), double vision, proptosis(Graves)

Question 7

what hair/skin changes are associated with thyrotoxicosis

Answer 7

hair change to brittle and thin hair, rapid fingernail growth

Question 8

what reproductive and muscle signs/symptoms are associated with thyrotoxicosis

Answer 8

reproductive = menstrual cycle changes, eg lighter bleeding and less frequent periods
muscles = muscles weakness, esp. upper arms and thighs

Question 9

what metabolic and thermogenesis signs/symptoms are associated with thyrotoxicosis

Answer 9

metabolic = weight loss despite increased appetite
thermogenesis = intolerance to heat

Question 10

what conditions cause hyperthyroidism/thyrotoxicosis as a result of excessive thyroid stimulation

Answer 10

Graves disease, Hashitoxicosis, thyrotropinoma, thyroid cancer, choriocarcinoma

Question 11

what conditions cause hyperthyroidism/thyrotoxicosis as a result of thyroid nodules with autonomous function

Answer 11

toxic solitary nodule and toxic multinodular goitre

Question 12

what changes in T3, T4 and TSH are seen in primary and secondary hyperthyroidism

Answer 12

primary = high free T3 + T4, low TSH
secondary = increased T3 + T4, high or normal TSH

Question 13

what is pretibial myxoedema

Answer 13

rare clinical sign specific to Graves’ disease, results in an infiltrative dermopathy

Question 14

what different types of conditions can cause thyrotoxicosis that are NOT associated with hyperthyroidism

Answer 14

thyroiditis, exogenous thyroid hormone, ectopic thyroid tissue

Question 15

give 2 examples of thyroiditis that can cause thyrotoxicosis that are NOT associated with hyperthyroidism

Answer 15

subacute(de Quervain’s) thyroiditis, post-partum thyroiditis

Question 16

when does Graves’ disease usually present and what precipitating factors are there

Answer 16

young(20-50y/o), interacting susceptibility genes 70% of cause, rest environmental such as smoking

Question 17

what clinical signs are specific to Graves’ disease

Answer 17

thyroid acropachy, thyroid bruit, Graves eye disease(ie Graves opthalmopathy)

Question 18

what is the most common cause of hyperthyroidism

Answer 18

Graves disease(85%)

Question 19

describe the characteristics/onset of nodular thyroid disease

Answer 19

older patients, insidious onset, thyroid may feel nodular, asymmetrical goitre(smooth in Graves)

Question 20

what tests can be done for nodular thyroid disease

Answer 20

high free T3 and T4, low TSH, antibody negative(TRAb) and scintigraphy = high uptake

Question 21

what thyroid autoantibodies are seen in Graves disease

Answer 21

anti-TPO antibody(70-80%), auto-thyroglobulin antibody(30-50%), TSH receptor antibody(70-100%)

Question 22

what clinical features are seen in a thyroid storm

Answer 22

severe hyperthyroidism, resp and cardiac collapse, hyperthermia
(medical emergency)

Question 23

in what patients is a thyroid storm typically seen in

Answer 23

hyperthyroid patients with an acute infection/illness or recent thyroid surgery

Question 24

what treatment is used for a thyroid storm

Answer 24

Lugol’s iodine, glucocorticoids, PTU, beta-blockers, fluids, monitoring

Question 25

what is the triad of typical clinical signs seen in Graves’ disease

Answer 25

hyperthyroidism with diffuse enlargement of thyroid gland, ophthalmology, pretibial myxoedema