Hypothyroidism

Question 1

symptoms of hypothyroidism

Answer 1

• Lethargy
• Cold intolerance
• ↓ appetite but ↑wt.
• Constipation
• Menorrhagia
• ↓ mood

Question 2

signs of hypothyroidism

Answer 2

• Cold hands
• Bradycardic
• Slow-relaxing reflexes
• Dry hair and skin
• Puffy face
• Goitre
• Myopathy, neuropathy
• Ascites
• Myxoedema

Question 3

what is myxoedema

Answer 3

• SC tissue swelling in severe hypothyroidism

- Typically around eyes and dorsum of hand

Question 4

primary causes of hypothyroidism

Answer 4

• Atrophic thyroiditis (commonest UK)
• Hashimoto’s thyroiditis
• Subacute thyroiditis (e.g. post-partum)
• Post De Quervain’s thyroiditis
• Iodine deficiency (commonest worldwide)
• Drugs: carbimazole, amiodarone, lithium
• Congenital: thyroid agenesis

Question 5

other causes of hypothyroidism

Answer 5

• thyroidectomy
• radio-iodine
• hypopituitarism (very rare cause)

Question 6

features of atrophic thyroiditis

Answer 6

• Thyroid antibodies +ve: anti-TPO, anti-TSH
• Lymphocytic infiltrate → atrophy (no goitre)
• Associations (Pernicious anaemia, Vitiligo, Endocrinopathies)

Question 7

features of Hashimoto’s thyroiditis

Answer 7

• TPO +ve
• Atrophy + regeneration → goitre
• May go through initial thyrotoxicosis phase
• May be euthyroid or hypothyoid

Question 8

investigations for hypothyroidism

Answer 8

• ↑TSH, ↓T3/T4
• ↑MCV ± normochromic anaemia
• ↑ triglyceride + ↑ cholesterol
• Hyponatraemia (SIADH)
• ↑ CK if assoc. myopathy
• Antibodies: TPO, TSH

Question 9

treatment for hypothyroidism

Answer 9

1. Levothyroxine
   - Titrate to normalise TSH
   - Enzyme inducers ↑ thyroxine metabolism
   - Clinical improvement takes ~2wks
2. Check for other AI disease: e.g. Addison’s, PA

Question 10

features of myxoedema coma

Answer 10

• Looks hypothyroid
• Hypothermia
• Hypoglycaemia
• Heart failure: bradycardia and ↓BP
• Coma and seizures

Question 11

precipitants to myxoedema coma

Answer 11

• Radioiodine
• Thyroidectomy
• Pituitary surgery
• Infection, trauma, MI, stroke

Question 12

management of myxoedema coma

Answer 12

• Bloods: TFTs, FBC, U+E, glucose, cortisol
• Correct any hypoglycaemia
• T3/T4 IV slowly (may ppt. myocardial ischaemia)
• Hydrocortisone 100mg IV
• Rx hypothermia and heart failure