Thyrotoxicosis

Question 1

Definition of thyrotoxicosis

Answer 1

The clinical effect of excess thyroid hormone, usually from gland hyperfunction

Question 2

Aetiology of thyrotoxicosis

Answer 2

• Graves’ disease:
◦ Accounts for most cases of thyrotoxicosis
◦ Due to circulating IgG auto-antibodies that bind to TSH receptors and cause smooth thyroid enlargement and increased hormone production
• Toxic multinodular goitre: Seen in elderly and in iodine deficient areas. These are nodules that secrete thyroid hormones
• Subacute de Quervain’s thyroiditis
• Exogenous: iodine excess, levothyroxine excess

Question 3

History and examination of thyrotoxicosis

Answer 3

• Weight loss
• Diarrhoea
• Sweating
• Heat intolerance
• Palpitations
• Tremor
• Irritability
• Over active/restlessness/anxiety
• Oligomenorrhoea
• Goitre presence
• Lid lag
• Exophthalmos
• Pretibial myxoedema
• Thyroid acropachy: looks like clubbing

Question 4

Investigations for thyrotoxicosis

Answer 4

• TSH: reduced due to increased thyroid hormones suppressing it
• T3 and T4: increased
• Thyroid autoantibodies: likely to be present

Question 5

Treatment for thyrotoxicosis

Answer 5

• Drugs:
‣ Beta Blockers (e.g propranolol) for rapid control of symptoms
‣ Give Carbimazole alongside this (reduce according to TFTs every 1-2months)

• Radioiodine:
• Clears out the thyroid gland
• Most become hypothyroid after
• No increase in risk of cancer

• Thyroidectomy:
◦ Usually total
◦ Risk of damage to recurrent laryngeal nerve (hoarse voice)
◦ Patient will become hypothyroid and will need thyroid hormone replacement

Question 6

Complications of thyrotoxicosis

Answer 6

• Thyroid storm: if not controlled
• Heart failure
• Angina
• AF
• Osteoporosis