hypothyroidism
| Etiology | Autoimmune, iodine deficiency, destruction of thyroid e.g. after radiotherapy, thyroidectomy (a no-brainer there tbh), infiltrative diseases. Causative drugs: lithium, amiodarone, aminoglutethimide, interferon alpha, thalidomide, stavudine, tyrosine kinase inhibitors, alemtuzumab, and immune checkpoint inhibitors (e.g., nivolumab, pembrolizumab, ipilimumab) |
| Epidemiology | |
| Clinical presentation | lethargy, depression, dry skin, goitre, postural hypotension, amenorrhea bradycardia non-pitting oedema, loss of lateral eyebrow, periorbital oedema ECG changes: prolonged PR interval, prolonged QT interval |
| Pathogenesis | |
| Diagnostic investigations | TFTs: expect ↑ TSH, ↓ fT4 in primary hypothyroidism May be associated with T1DM Anti-TPO (for Hashimoto's thyroiditis) |
| Management | Replace thyroxine, naturally. Start with lower dose if coronary artery disease or age >65 |
textbook signs of hypothyroidism
- CVS: bradycardia, ↓ cardiac output, ↑ blood cholesterol
- GI: constipation
- myxoedema = ↑ interstitial fluid, not to be mistaken with pretibial myxoedema which for some reason is incredibly different...