ENDO-HYPOThy

Question 1

Describe Hypothyroidism

Answer 1

Hypometabolic state resulting from insufficient production of thyroid hormones

Question 2

Describe Primary hypothyroidism

Answer 2

high TSH with low T4 = thyroid gland etiology

Question 3

Describe Secondary hypothyroidism

Answer 3

low TSH with low T4 = pituitary or hypothalamic etiology (less common); referred to endocrine

Question 4

Who is more affected by thyroid disease

Answer 4

3 times more likely in women than in men

Question 5

What is the most common cause of Hypothyroidism

Answer 5

1] dietary iodine deficiency (developing countries), 2] In the US, Autoimmune destruction of the thyroid (Hashimoto’s thyroiditis), 3] Iatrogenic, 4] Drug induced

Question 6

What antibodies are invovled in Hashimoto’s thyroiditis

Answer 6

Anti-thyroid peroxidase antibodies; Anti-thyroglobulin antibodies

Question 7

Describe the Iatrogenic cause of Hypothyroidism

Answer 7

resulting from hyperthyroid or thyroid cancer treatment (RAI, thyroidectomy)

Question 8

Describe the drug induced cause of Hypothyroidism

Answer 8

lithium, amiodarone, thalidomide

Question 9

Describe the onset of Hypothyroidism

Answer 9

insidious

Question 10

What are the clinical features of Hypothyroidism

Answer 10

Fatigue, lethargy, increased sleep requirement, impaired mental function, depression, cold intolerance, weakness, myalgias ,weight gain, hair loss, skin & nail changes (dry, brittle, scaling), constipation, hoarseness, dysphagia, edema, menstrual irregularities (increased risk of miscarriage, infertility)

Question 11

What are the physical exam findings of Hypothyroidism

Answer 11

palpable goiter, bradycardia, decreased tendon reflexes, macroglossia

Question 12

Describe a goiter

Answer 12

enlarged thyroid gland; most common thyroid abnormality

Question 13

Describe what an Endemic goiter indicates

Answer 13

iodine deficiency goiter

Question 14

Describe what an Goiter + hyperthyroidism indicates

Answer 14

1] Graves disease, 2] toxic multinodular goiter; hot nodule

Question 15

Describe what an Goiter + hypothyroidism indicates

Answer 15

Hashimoto’s thyroiditis

Question 16

Describe the treatment of Goiters

Answer 16

1] Goiters often decrease in size with thyroid treatment (hyper/hypothyroid medication, RAI), 2] sometimes surgery indicated due to goiter affecting swallowing or causing airway obstruction

Question 17

Describe the diagnostic values of Primary hypothyroidism

Answer 17

high TSH with low/low normal free T4

Question 18

Describe the diagnostic values of Secondary hypothyroidism

Answer 18

low TSH with low free T4

Question 19

What are additonal tests that confirm hypothyroidism?

Answer 19

1] Positive TPOAb or TgAb in autoimmune disease, 2] Decreased uptake on thyroid scan, 3] Additional lab findings can include anemia, elevated LDL, hyponatremia

Question 20

What is the other name for Hashimoto’s Thyroiditis and why

Answer 20

Chronic Lymphocytic Thyroiditis because lymphocytic infiltration and destruction of thyroid tissue

Question 21

What is the most common cause of hypothyroidism

Answer 21

Hashimoto’s Thyroiditis

Question 22

Describe who is commonly affected by hypothyroidism

Answer 22

Most commonly affects women age 30-60, often family history present

Question 23

List the findings of Hashimoto’s Thyroiditis

Answer 23

1] Associated with high titers of autoantibodies (TPOAb and/or TgAb), 2] Goiter is common finding

Question 24

What is the treatment for Hashimoto’s Thyroiditis

Answer 24

lifelong replacement therapy due to autoimmune thyroid gland failure

Question 25

Describe Thyroid hormone replacement

Answer 25

levothyroxine (Synthroid, Levoxyl, Levothroid, Tirosint)

Question 26

What is the dosing for levothyroxine

Answer 26

1.7mcg/kg po qd (once daily dose, best taken on empty stomach in the morning)

Question 27

Describe the approach to levothyroxine intiation

Answer 27

1] Conservative initial therapy: incremental increase to slowly achieve restoration of normal metabolic rate 50 mcg; 2] Children, elderly or cardiac pts. start tx at low dosage

Question 28

Describe the clinical response of levothyroxine

Answer 28

Full clinical response usually takes several months, ideally repeat labs 4-6 weeks after starting therapy and adjust dose prn

Question 29

Describe the target response of levothyroxine

Answer 29

TSH and T4 both within normal range- euthyroid

Question 30

What is a complication of hypothyroidism

Answer 30

Myxedema Coma

Question 31

Describe a Myxedema Coma

Answer 31

Severe hypothyroidism, often fatal, Medical emergency with high mortality rate as Respiratory failure is a major concern

Question 32

Who is more at risk for Myxedema Coma

Answer 32

More typically seen in the elderly with long-standing, untreated hypothyroidism; Often precipitated by acute event: infection (pneumonia, peritonitis), MI, CVA, trauma

Question 33

Define Myxedema

Answer 33

generalized skin and soft tissue swelling due to abnormal deposits of mucin

Question 34

Describe the clinical findings of Myxedema Coma

Answer 34

1] Skin: extensive scaling, dry, cold; appears thickened or “doughy”; yellow-orange discoloration; periorbital edema and nonpitting edema throughout, 2] Sinus bradycardia, hypotension, hypoventilation, pericardial effusion, pleural effusion, ascites, 3] Decreased mental status, slowed speech, ataxia