Hypothyroidism

Question 1

What is hypothyroidism?

Answer 1

Hypothyroidism is a condition where the thyroid gland produces insufficient thyroid hormones, leading to a slowdown of metabolic processes.

Question 2

What are the common symptoms of hypothyroidism?

Answer 2

Fatigue, weight gain, cold intolerance, dry skin, constipation, depression, and bradycardia.

Question 3

What are the common causes of primary hypothyroidism?

Answer 3

Hashimoto’s thyroiditis, iodine deficiency, thyroidectomy, radioiodine therapy, and certain medications (e.g., amiodarone, lithium).

Question 4

What is the most common cause of hypothyroidism in iodine-sufficient regions?

Answer 4

Hashimoto’s thyroiditis, an autoimmune condition.

Question 5

What is the pathophysiology of Hashimoto’s thyroiditis?

Answer 5

Autoimmune destruction of the thyroid gland leads to reduced thyroid hormone production and eventual hypothyroidism.

Question 6

What are the secondary causes of hypothyroidism?

Answer 6

Secondary hypothyroidism is caused by pituitary dysfunction resulting in reduced TSH production, often due to tumours, surgery, or trauma.

Question 7

What are the clinical signs of hypothyroidism on examination?

Answer 7

Dry skin, bradycardia, facial puffiness, hoarseness, goitre, slow-relaxing reflexes, and hair thinning.

Question 8

How does hypothyroidism affect metabolism?

Answer 8

Reduced thyroid hormone levels slow metabolic processes, leading to weight gain, cold intolerance, and fatigue.

Question 9

What are the effects of hypothyroidism on the cardiovascular system?

Answer 9

Bradycardia, reduced cardiac output, and in severe cases, pericardial effusion or heart failure.

Question 10

What are the effects of hypothyroidism on the gastrointestinal system?

Answer 10

Hypothyroidism causes reduced gut motility, leading to constipation.

Question 11

What are the effects of hypothyroidism on the skin and hair?

Answer 11

Dry, coarse skin, brittle hair, and hair thinning, including lateral eyebrow loss.

Question 12

What are the typical biochemical findings in primary hypothyroidism?

Answer 12

High TSH and low free T4 levels.

Question 13

What are the typical biochemical findings in secondary hypothyroidism?

Answer 13

Low or inappropriately normal TSH and low free T4 levels.

Question 14

What additional investigations can support the diagnosis of Hashimoto’s thyroiditis?

Answer 14

Testing for anti-thyroid peroxidase (TPO) antibodies, which are commonly elevated in Hashimoto’s thyroiditis.

Question 15

What is subclinical hypothyroidism?

Answer 15

A condition characterised by elevated TSH with normal free T4 levels, often without symptoms.

Question 16

What is the first-line treatment for hypothyroidism?

Answer 16

Levothyroxine, a synthetic form of T4, is the first-line treatment.

Question 17

How is the dose of levothyroxine monitored?

Answer 17

By measuring TSH levels and adjusting the dose to maintain TSH within the reference range.

Question 18

What is myxoedema?

Answer 18

Severe, untreated hypothyroidism presenting with symptoms such as hypothermia, bradycardia, confusion, and myxoedema coma in extreme cases.

Question 19

How is myxoedema coma managed?

Answer 19

Intravenous levothyroxine, supportive care (e.g., warming, fluid resuscitation), and treatment of underlying triggers like infection.

Question 20

What are the complications of untreated hypothyroidism?

Answer 20

Cardiovascular disease, infertility, myxoedema coma, and in pregnant women, adverse effects on foetal development.

Question 21

How does hypothyroidism affect cholesterol levels?

Answer 21

Hypothyroidism can cause hypercholesterolaemia due to reduced lipid metabolism.

Question 22

What are the risk factors for hypothyroidism?

Answer 22

Female sex, age over 60, family history of thyroid disease, autoimmune conditions, and iodine deficiency.

Question 23

What is the role of iodine in thyroid function?

Answer 23

Iodine is essential for the synthesis of thyroid hormones T3 and T4.

Question 24

What are the common differential diagnoses for hypothyroidism?

Answer 24

Depression, chronic fatigue syndrome, anaemia, and other causes of weight gain or fatigue.

Question 25

What lifestyle advice should be given to patients with hypothyroidism?

Answer 25

Take levothyroxine on an empty stomach, monitor symptoms and TSH regularly, and maintain a balanced diet to avoid excessive iodine intake.