Hypothyroidism

Question 1

What is hypothyroidism?

Answer 1

clinical syndrome resulting from insufficient secretion of thyroid hormones

Question 2

List 3 types of hypothyroidism and where the pathology lies

Answer 2

Primary (thyroid gland)
Secondary (pituitary gland)
Tertiary (hypothalamus)

Question 3

List 5 types of acquired primary hypothyroidism

Answer 3

Hashimoto's thyroiditis (AI)  
Iatrogenic (post-surgery, radioiodine, hyperthyroid medication) 
Severe iodine deficiency  
Iodine excess (Wolff-Chaikoff effect)  
Thyroiditis

Question 4

What are 2 congenital types of primary hypothyroidism?

Answer 4

Thyroid dysgenesis

Inherited defects in thyroid hormone biosynthesis

Question 5

Give 3 facts on the epidemiology of hypothyroidism

Answer 5

Increases with age
F > M
Most common age of onset 60 yrs

Question 6

What is often the nature of onset of symptoms in hypothyroidism?

Answer 6

Insidious

Non specific symptoms

Question 7

List 14 symptoms of hypothyroidism

Answer 7

Cold intolerance  
Lethargy  
Weight gain  
Reduced appetite  
Constipation  
Dry skin  
Hair loss  
Hoarse voice  
Mental slowness 
Depression  
Cramps  
Ataxia  
Paraesthesia 
Menstrual disturbance

Question 8

What histories may be significant in a patient with a potentially hypothyroid?

Answer 8

Surgery/ radioiodine therapy for hyperthyroidism

Personal/ FH of other AI conditions (e.g. Addison’s, T1DM)

Question 9

List 6 signs of Myxoedema coma. In which patients do you most often see presenting like this?

Answer 9

Hypothermia 
Hypoventilation 
Hyponatraemia 
Heart failure  
Confusion  
Coma
Elderly

Question 10

What 2 signs may be noticeable on examination of the hands of a patient with hypothyroid?

Answer 10

Bradycardia

Cold hands

Question 11

What 6 signs may be noticeable on examination of the Head/Neck/Skin of a patient with hypothyroid?

Answer 11

Pale puffy face  
Goitre  
Oedema  
Hair loss  
Dry skin  
Vitiligo

Question 12

What signs may be noticeable on examination of the chest of a patient with hypothyroid?

Answer 12

Pericardial effusion

Pleural effusion

Question 13

What signs may be noticeable on examination of the abdomen of a patient with hypothyroid?

Answer 13

Ascites

Question 14

What neurological signs may be noticeable on examination of a patient with hypothyroid?

Answer 14

Slow relaxation of reflexes

Signs of carpal tunnel syndrome

Question 15

What is investigated in a blood test of a patient with suspected hypothyroid?

Answer 15

TFTs
FBC: may show normocytic anaemia
U+Es: may show low sodium
Cholesterol: may be high

Question 16

Describe the TFTs in primary hypothyroidism

Answer 16

TSH: High
T4: Low
T3: Low/ Normal

Question 17

Describe the TFTs in secondary hypothyroidism

Answer 17

TSH: Low/ Normal
T4: Low
T3: Low/ Normal

Question 18

What medication is used in treatment of chronic hypothyroidism?

Answer 18

Levothyroxine sodium

50-100 micrograms OD

Question 19

What is it important to exclude before starting thyroid hormone replacement?

Answer 19

Adrenal insufficiency- would precipitate Addisonian crisis

Question 20

What is involved in the management of a myxoedema coma?

Answer 20

IV levothyroxine
Oxygen, Rewarming, Rehydration
IV hydrocortisone
Treat underlying cause (e.g. infection)

Question 21

List 2 complications of hypothyroidism

Answer 21

Myxoedema coma  
Myxoedema madness (psychosis with delusions + hallucinations or dementia)

Question 22

Summarise the prognosis for hypothyroidism

Answer 22

Lifelong levothyroxine is required

Myxoedema coma mortality = 80%