Thyrotoxicosis

Question 1

What is thyrotoxicosis?

Answer 1

Thyrotoxicosis refers to the clinical syndrome caused by excess circulating thyroid hormones, regardless of the cause.

Question 2

What is hyperthyroidism?

Answer 2

Hyperthyroidism is a specific cause of thyrotoxicosis due to excessive thyroid hormone production by the thyroid gland.

Question 3

What are the common symptoms of thyrotoxicosis?

Answer 3

Weight loss, heat intolerance, palpitations, tremor, increased appetite, sweating, anxiety, and diarrhoea.

Question 4

What are the common signs of thyrotoxicosis on examination?

Answer 4

Tachycardia, goitre, tremor, warm moist skin, lid lag, and exophthalmos (in Graves’ disease).

Question 5

What are the common causes of thyrotoxicosis?

Answer 5

Graves’ disease, toxic multinodular goitre, toxic adenoma, and thyroiditis.

Question 6

What is the most common cause of hyperthyroidism?

Answer 6

Graves’ disease is the most common cause of hyperthyroidism.

Question 7

What is the pathophysiology of Graves’ disease?

Answer 7

Graves’ disease is an autoimmune condition where thyroid-stimulating antibodies stimulate TSH receptors, leading to increased thyroid hormone production.

Question 8

What is the pathophysiology of toxic multinodular goitre?

Answer 8

Autonomous hyperfunctioning nodules in the thyroid gland produce excessive thyroid hormones, independent of TSH regulation.

Question 9

What is the typical age of onset for Graves’ disease?

Answer 9

Graves’ disease commonly affects women aged 20-40 years.

Question 10

What are the risk factors for hyperthyroidism?

Answer 10

Female sex, family history of thyroid disorders, autoimmune diseases, and iodine excess.

Question 11

What are the characteristic eye signs in Graves’ disease?

Answer 11

Exophthalmos, lid lag, lid retraction, and conjunctival injection.

Question 12

What are the features of thyroid storm (thyrotoxic crisis)?

Answer 12

Fever, tachycardia, hypertension, agitation, confusion, and multi-organ dysfunction.

Question 13

What investigations are used to diagnose thyrotoxicosis?

Answer 13

TFTs (low TSH, high free T4 and/or T3), thyroid antibodies, and imaging such as thyroid ultrasound or radioisotope scanning.

Question 14

What is the role of thyroid-stimulating hormone receptor antibodies (TRAb)?

Answer 14

TRAb is a specific marker for Graves’ disease and helps differentiate it from other causes of thyrotoxicosis.

Question 15

What are the typical TFT findings in primary hyperthyroidism?

Answer 15

Low TSH and high free T4 and/or free T3 levels.

Question 16

What is the role of thyroid ultrasound in thyrotoxicosis?

Answer 16

It helps identify structural abnormalities like nodules and assess for increased vascularity seen in Graves’ disease.

Question 17

What is the first-line treatment for Graves’ disease?

Answer 17

Anti-thyroid drugs, such as carbimazole or propylthiouracil, are typically used as the first-line treatment.

Question 18

What are the treatment options for hyperthyroidism?

Answer 18

Treatment options include anti-thyroid drugs, radioactive iodine therapy, and thyroidectomy.

Question 19

What is the mechanism of action of anti-thyroid drugs like carbimazole?

Answer 19

They inhibit thyroid hormone synthesis by blocking the enzyme thyroid peroxidase.

Question 20

When is radioactive iodine therapy indicated in hyperthyroidism?

Answer 20

It is indicated in cases of recurrent Graves’ disease, toxic multinodular goitre, or toxic adenoma.

Question 21

What are the complications of untreated hyperthyroidism?

Answer 21

Complications include atrial fibrillation, heart failure, osteoporosis, and thyroid storm.

Question 22

How is thyroid storm managed?

Answer 22

Management includes high-dose beta-blockers, anti-thyroid drugs, glucocorticoids, and supportive care in an intensive care setting.

Question 23

What are the side effects of carbimazole?

Answer 23

Side effects include rash, agranulocytosis, and hepatotoxicity.

Question 24

What are the long-term risks of radioactive iodine therapy?

Answer 24

Long-term risks include hypothyroidism and, rarely, radiation-induced thyroiditis or cancer.

Question 25

What is the role of thyroidectomy in hyperthyroidism?

Answer 25

Thyroidectomy is indicated for large goitres, suspicion of malignancy, or in patients unresponsive to other treatments.