Hypothyroidism

Question 1

What is hypothyroidism?

Answer 1

Insufficient thyroid hormones T3 and T4 (thyroxine)

Hypothyroidism can lead to various clinical symptoms and complications if not managed properly.

Question 2

Pathophysiology of primary hypothyroidism?

Answer 2

Thyroid behaves abnormally → inadequate hormone production; negative feedback → increased TSH

In primary hypothyroidism, the thyroid gland fails to produce enough hormones, leading to elevated TSH levels.

Question 3

Pathophysiology of secondary hypothyroidism?

Answer 3

Pituitary behaves abnormally → inadequate TSH; understimulated thyroid → low T3 and T4

Secondary hypothyroidism results from issues with the pituitary gland affecting TSH production.

Question 4

What are the TSH and T3/T4 levels in primary hypothyroidism?

Answer 4

High TSH and low T3 and T4

Primary hypothyroidism is identified by elevated TSH due to lack of thyroid hormone production.

Question 5

What are the TSH and T3/T4 levels in secondary hypothyroidism?

Answer 5

Low TSH and low T3 and T4

In secondary hypothyroidism, both TSH and thyroid hormones are low due to pituitary dysfunction.

Question 6

What is the most common cause of primary hypothyroidism in the developed world?

Answer 6

Hashimoto’s thyroiditis

Hashimoto’s thyroiditis is an autoimmune disorder leading to inflammation and destruction of the thyroid gland.

Question 7

What is iodine deficiency known for in relation to hypothyroidism?

Answer 7

Most common cause of hypothyroid in developing world

Iodine is essential for thyroid hormone production; deficiency leads to hypothyroidism.

Question 8

Name one drug that can cause hypothyroidism.

Answer 8

Lithium

(also amiodarone)

Lithium inhibits thyroid hormone production, potentially leading to goitre and hypothyroidism.

Question 9

What are some clinical features of hypothyroidism?

Answer 9

• Weight gain
• Fatigue
• Dry skin
• Coarse hair and hair loss
• Fluid retention
• Heavy or irregular periods
• Constipation
• Goitre

These symptoms arise from the decreased metabolic activity associated with low thyroid hormone levels.

Question 10

What is the standard medical therapy for hypothyroidism?

Answer 10

Levothyroxine

Levothyroxine is a synthetic form of T4 that is converted to T3 in the body.

Question 11

How is the levothyroxine dose adjusted based on TSH levels?

Answer 11

• High TSH: Increase dose
• Low TSH: Decrease dose

TSH levels guide the titration of levothyroxine to maintain normal thyroid hormone levels.

Question 12

What characterizes subclinical hypothyroidism?

Answer 12

Elevated TSH and normal T4 levels

Subclinical hypothyroidism is often asymptomatic and may require monitoring or treatment.

Question 13

What is the main concern with undiagnosed hypothyroidism in children?

Answer 13

Can lead to significant problems with neurodevelopment and intellectual disability

Early detection and treatment are crucial for healthy development.

Question 14

What are the causes of congenital hypothyroidism?

Answer 14

• Thyroid dysgenesis
• Dyshormonogenesis

Congenital hypothyroidism can result from developmental issues with the thyroid gland or its hormone production capability.

Question 15

What are some symptoms of acquired hypothyroidism in children?

Answer 15

• Fatigue and low energy
• Poor growth
• Weight gain
• Poor school performance
• Constipation
• Dry skin and hair loss

Symptoms may vary and can impact a child’s overall growth and development.