Hypothyroidism

Question 1

define hypothyroidism?

Answer 1

the clinical syndrome resulting from insufficiency secretion of thyroid hormones
categorised into
- primary hypothyroidism
- secondary hypothyroidism,

Question 2

define primary hypothyroidism?

Answer 2

o decreased thyroid hormone production from the thyroid

Question 3

define secondary hypothyroidism?

Answer 3

o Pituitary and Hypothalamic Disease - resulting in reduced TSH, hence, reduced stimulation of thyroid hormone production

Question 4

what are the causes of primary hypothyroidism?

Answer 4

•	Hashimoto's thyroiditis 
•	Iatrogenic 
•	Severe dietary iodine deficiency  
•	Iodine excess 
•	Subacute Thyroiditis (De Quervains) 
o	Congenital

Question 5

features of hashimotos?

Answer 5

o Autoimmune cause
o Thyrotoxicosis in the acute phase
o More common in women
o Associated with T1DM, addisons, pernicious anaemia

Question 6

features of iatrogenic hypothyroidism?

Answer 6

o Post-surgery
o Radioiodine
o Carbimazole
o Lithium

Question 7

features of severe lithium iodine deficiency?

Answer 7

o Common in the developing world

o Common in mountainous areas

Question 8

features of iodine excess?

Answer 8

o Wolff-Chaikoff effect

o Associated with taking amiodarone

Question 9

features of subacute thyroiditis?

Answer 9

o Post viral infection

o Presents initially with hyperthyroidism

Question 10

what causes secondary hypothyroidism?

Answer 10

o Pituitary and Hypothalamic Disease

Question 11

epidemiology of hypothyroidism?

Answer 11

• more common in females

- age of onset >40

Question 12

presenting symptoms of hypothyroidism?

Answer 12

Weight gain 
Lethargy 
Cold intolerance 
Dry (anhydrosis), cold, yellowish skin
Non-pitting oedema (e.g. hands, face)
Dry, coarse scalp hair, loss of lateral aspect of eyebrows
Constipation
Menorrhagia
Decreased deep tendon reflexes
Carpal tunnel syndrome

Question 13

features of a myxoedema coma?

Answer 13

o	Hypothermia 
o	Hypoventilation 
o	Hyponatraemia 
o	Heart failure  
o	Hyporeflexia
o	Bradycardia 
o	Seizures 
o	Confusion  
o	Coma

Question 14

signs of hypothyroidism in the hands?

Answer 14

o Bradycardia

o Cold hands

Question 15

signs of hypothyroidism in Head/Neck/Skin?

Answer 15

o	Pale puffy face  
o	Goitre  
o	Oedema  
o	Hair loss  
o	Dry skin  
o	Vitiligo

Question 16

signs of hypothyroidism in chest?

Answer 16

o Pericardial effusion

o Pleural effusion

Question 17

signs of hypothyroidism in the abdomen?

Answer 17

o Ascites

Question 18

signs of hypothyroidism neurologically?

Answer 18

o Slow relaxation of reflexes

o Signs of carpal tunnel syndrome

Question 19

what blood results might you get?

Answer 19

o TFTs – TSH, T4, T3
Primary hypothyroidism = high TSH, low T4
Secondary hypothyroidism = low TSH, low T4
o FBC - may show normocytic anaemia
o U&Es - may show low sodium
o Cholesterol - may be high
o Autoantibodies

Question 20

which bloods are most important?

Answer 20

TSH

Question 21

what antibodies should be monitored?

Answer 21

• Anti-thyroid peroxidase (hashimotos)
• TSH receptor antibodies (graves)
• Thyroglobulin antibodies

Question 22

how is hypothyroidism treated?

Answer 22

o Levothyroxine

Question 23

how to manage MYXOEDEMA COMA ?

Answer 23

o	Oxygen  
o	Rewarming  
o	Rehydration  
o	IV T4/T3 
o	IV hydrocortisone  
o	Treat underlying cause

Question 24

complications of hypothyroidism?

Answer 24

• Myxoedema coma
• Myxoedema madness
• Over-replacement with thyroxine increases risk of osteoporosis

Question 25

prognosis?

Answer 25

• Lifelong levothyroxine is required

* Myxoedema coma mortality = 80%