Thyroid

Question 1

Where is the thyroid gland located?

Answer 1

Anterior aspect of the neck inferior to the cricoid cartilage

Question 2

What is the anatomy of the thyroid gland?

Answer 2

Isthmus connects the 2 lobes of the thyroid gland

Fibrous septa divide the gland into pseudo gout composed of follicles

Question 3

Where does the thyroid gland develop from?

Answer 3

Floor of the pharynx
+
Descends to location giving rise to the Thyroglossal duct

Question 4

What hormones are produced by the thyroid gland?

What is the main substance needed to produce them?

Answer 4

T3
T4

Iodine

Question 5

How do thyroid hormones circulate around the body?

Answer 5

Thyroid binding globulin (TBG)
Albumin
TTH
Free circulating

Question 6

What is hyperthyroidism?

Answer 6

When thyroid gland produces too much T3 and T4

Question 7

What are the different types of hyperthyroidism?

Answer 7

Primary hyperthyroidism
Secondary hyperthyroidism
Subclincal hyperthyroidism
Graves
Toxic multi Nodular goitre

Question 8

What is a primary hyperthyroidism?

Answer 8

Where the thyroid gland produces too much T3 T4 independant to the pituitary gland

Question 9

What is secondary hyperthyroidism?

Answer 9

When too much TSH is being produced leading to the thyroid gland making too much T3 and T4

(Hypothalamus/pituitary issue)

Question 10

Is there normally more T3 or T4 in the body?

Answer 10

T4

Question 11

What are the TSH, T3 and T4 levels in a patient with primary hyperthyroidism?

Answer 11

TSH - Extremely low/undetectable
T4 - Very high
T3 - High

Question 12

What are the TSH, T3 and T4 levels in a patient with secondary hyperthyroidism?

Answer 12

TSH - High
T4 - High
T3 - High

Question 13

What are the TSH, T3 and T4 levels in a patient with subclinical hyperthyroidism?

Answer 13

TSH - Low
T4 - normal
T3 - normal

Question 14

What are the symptoms of hyperthyroidism?

Answer 14

Palpitations
Sweaty
Shaking
Weight loss
Diarrhoea
Agitation
Dysmenorrhoea
Heat intolerance

Question 15

What are the signs of hyperthyroidism?

Answer 15

Tachycardia
AF
Tremor
Hyperkinetic
Palmar erythema
Congestive heart failure
Chorea
Psychosis
Goitre

Question 16

What are some signs of hyperthyroidism specific to graves?

Answer 16

Ophthalmology signs like exophthalmos
Dermropahy (thyroid acropachy)
Lymphoid hyperplasia
Pretibial Myxoedema

Question 17

What are some causes of hyperthyroidism?

Answer 17

Graves’ disease
Solitary toxic thyroid nodule
Toxic multi Nodular goitre
Thyroiditis
TSH secreting adenoma
Exogenous thyroid hormones

Question 18

What is the pathophysiology of Graves’ disease?

Answer 18

Auto antibodies attach to TSH receptors making the thyroid produce lots of T3 and T4 since it thinks theres lots of TSH in the body

Question 19

What specific features does Graves’ disease have that other hyperthyroidisms dont?

Answer 19

Diffuse non Nodular goitre
Thyroid acropachy (hand swelling and finger clubbing)
Pretibial Myxoedema
Exophthalmus (graves eye disease)

Question 20

How is Graves’ disease initially managed?

Answer 20

Carbimazole first line
If pregnant give PTU

B blockers for symptom relief (Propranolol)

Question 21

How is Graves’ disease managed if the patient relapses following treatment?

Answer 21

Consider radioiodine or surgery

Question 22

What its thee pathophysiology behind a singular toxic thyroid nodule?

Answer 22

Single thyroid nodule = benign adenoma which secretes T3 and T4

Question 23

How is a solitary/singular thyroid nodule treated that’s causing hyperthyroidism?

Answer 23

Surgical removal

Question 24

What is the management for a toxic multi Nodular goitre causing hyperthyroidism?

Answer 24

Carbimazole but consider radioiodine or surgery sooner since more likely to relapse than graves

Question 25

How does Thyroiditis affect the thyroid gland?

Answer 25

Typically get a hyperthyroidism then ultimately a hypthyroidism picture

Question 26

What is De Quervains thyroiditis?

Answer 26

Subacute thyroiditis which leads to temporary inflammation of the thyroid gland

Question 27

What is the pathophysiology of De Quervains Thyroiditis?

Answer 27

Hyperthyroidism / thyrotoxicosis occurs due to inflammation Then hypothyroidism Then normal

Question 28

What is the management for De Quervains Thyroiditis?

Answer 28

Symptomatic management since self resolves NSAIDs for. Any pains Propranolol for symptoms Levothyroxine for hypothyroidism

Question 29

How is a secondary hyperthyroidism treated?

Answer 29

Transphenoidal surgery Pituitary radiotherapy

Question 30

What is a thyroid storm?

Answer 30

Severe case of hyperthyroidism / thyrotoxicosis

Question 31

How does a thyroid storm present?

Answer 31

Severe hyperthyroidism Ferber Tachycardia Delirium

Question 32

How is a thyroid storm managed?

Answer 32

Endocrinologist: PTU 200-300mcg/6hrs via NG or Carbimazole B blockers like propranolol 60mg Prednisolone Fluid resus Anti arrhythmias if needed

Question 33

What is a side effect/adverse reaction of Carbimazole?

Answer 33

Acute pancreatitis Agranulocytosis

Question 34

What is a side effect/adverse drug reaction to PTU (Propylthiouracil)?

Answer 34

Agranulocytosis Severe liver reactions

Question 35

What are the consequences of having thyroid surgery?

Answer 35

On levothyroxine for life Risk in surgery: -bleeding -anaesthetic risk -risk vocal cord palsy

Question 36

What are the precautions that need to be taken when treating a patient with radioactive iodine for hyperthyroidism?

Answer 36

Women must not be pregnant/breast feeding within 6months of treatment Men shouldn’t father children within 4 months of treatment Limit contact with children and pregnant woman after dose

Question 37

What is subclinical hyperthyroidism?

Answer 37

T4 and T3 are normal but TSH has become low

Question 38

What are the symptoms of hypothyroidism?

Answer 38

Fatigue Weight gain Lethargy Constipation Cold intolerance Amenorrhoea Dry skin Hoarse voice Carpal tunnel Depression

Question 39

What are the signs of hypothyroidism?

Answer 39

Bradycardia Heart block Odema Dry skin + nails Hyporeflexia

Question 40

What are the 2 types of hypothyroidism?

Answer 40

Primary hypothyroidism Secondary hypothyroidism

Question 41

What is primary hypothyroidism? What is secondary hypothyroidism?

Answer 41

Primary = Thyroid produces abnormally low T3 and T4 despite high TSH Secondary = pituitary makes low TSH so thyroid makes low T3 and T4

Question 42

What are some causes of primary hypothyroidism?

Answer 42

Hashimotos thyroiditis Iodine deficiency Hyperthyroidism treatments (Carbimazole, PTU, radioiodine and surgery) Lithium Amiodarone

Question 43

What are some causes of secondary hypothyroidism?

Answer 43

Pituitary adenoma Pituitary surgery Radiotherapy Sheehans syndrome Trauma

Question 44

What 2 causes of hypothyroidism can cause a goitre?

Answer 44

Hashimotos Thyroiditis Iodine deficiency

Question 45

How is hypothyroidism managed?

Answer 45

Life long levothyroxine Build up dose gradually (1.6mcg-1.8mcg/kg) TSH every 6 weeks then annually

Question 46

How must levothyroxine be taken?

Answer 46

1st thing in morning on empty stomach 30mins before food or other meds

Question 47

What conditions affect the absorption of levothyroxine?

Answer 47

Coeliacs H-pylori Lactose intolerance

Question 48

What is a Myxoedema coma?

Answer 48

Severe hypothyroidism

Question 49

How is a Myxoedema coma managed?

Answer 49

ABCDE Passive external. Warming. 0.5degrees/hr Thyroid hormone replacement - T4 300-500 mcg IV or. NG then 50-100mcg/day If no improvement in 24-48hrs consider giving T3

Question 50

What is the management for Graves if the patient is pregnant?

Answer 50

Propylthiouracil (PTU)