ENDOCRINOLOGY

Question 0

What is meant by primary hyperthyroidism?

Answer 0

Hyperthyroidism caused by an intrinsic thyroid abnormality.
Examples…Diffuse hyperplasia (Graves Disease)
Hyperfunctioning multinodular goiter
Hyperfunctioning adenoma
Iodine induced hyperthyroidism
Neonatal thyrotoxicosis
associated with maternal Graves Disease

Question 1

What is thyrotoxicosis also known as hyperthyroidism?

Answer 1

A hypermetabolic state caused by elevated circulating levels of free T3 and T4.

Question 2

What is meant by secondary hyperthyroidism?

Answer 2

Hyperthyroidism caused by processes outside of the thyroid gland
Example…TSH secreting pituitary tumor (adenoma)

Question 3

Clinical Manifestations of hyperthryroidism?

Answer 3

Warm, flushed skin
Tachycardia, palpitations, cardiomegaly
Tremor, hyperactivity, anxiety
Proptosis (protuberant appearance of eyeballs)
Gut hypermotility/diarrhea
Thyroid storm–medical emergency…Fever Tachycardia

Question 4

Hyperthyroidism is diagnosed by what?

Answer 4

Serum TSH is the most useful screening test
Levels are decreased in the earliest stages.
Free T4 is elevated

Question 5

What is hypothryroidism?

Answer 5

A condition caused by a structural or functional derangement that interferes with the production of thyroid hormone.

Question 6

Primary hypothyroidism is?

Answer 6

Hypothryoidism caused by intrinsic abnormality in the thyroid itself

• Genetic defects in thyroid development
• Thyroid hormone resistance syndrome
• Post ablative surgery, radioiodine therapy, or external radiation
• Autoimmune hypothyroidism (Hashimoto thyroiditis)
• Drugs (Lithium, iodides)
• Congenital biosynthetic defect

Question 7

What is secondary hypothyroidism?

Answer 7

Hypothyroidism caused by pituitary or hypothalamic disease

• Pituitary failure
• hypothalamic failure

Question 8

Worldwide Congenital hypothyroidism is most often a result of what?

Answer 8

Endemic iodine deficiency in the diet

Question 9

Hashimoto thyroiditis…what is it?

Answer 9

Autoimmune hypothyroidism..results in destruction of the thyroid gland and gradual progressive thyroid failure. Most common cause of hypothyroidism in the world where there is sufficient iodine levels.

Question 10

Hashimoto Thyroiditis Clinical Course…

Answer 10

Painless enlargement of thyroid (goiter) in a middle aged woman (most commonly affected) Free t4 and t3 levels are elevated TSH diminished and radioiodine uptake is decreased. (Hashitoxicosis)

• As hypothyroidism supervenes t4 and t3 levels fall and TSH is elevated.
• Hashimoto thyroiditis…individuals affected have increased risk for developing other autoimmune diseases.

Question 11

Graves Disease…

Answer 11

The most common cause of endogenous hyperthyroidism

Question 12

Graves Disease has a triad of clinical findings.. What are they?

Answer 12

Hyperthyroidism associated with

• diffuse enlargement of the gland
• Exopthalmos
• pretibial myxedema (dermopathy)

Question 13

Cretinisim refers to what?

Answer 13

Hyperthyroidism that develops in infancy or early childhood.

Question 14

Clinical Manifestations of cretinism are…

Answer 14

Impaired development of skeletal system
impaired development of central nervous system
severe mental retardation
short stature
protruding tongue
umbilical hernia