hypothyroid Flashcards
causes?
-hashimoto thyroiditis (most common cause in iodine-sufficient countries)
-de quervain (subacute thyroiditis)
-iodine deficiency (most common cause worldwide)
-iatrogenic (neck radiation, radioactive iodine therapy)
pathophysiology and presentation of hashimoto?
ABs against thyroid peroxidase and thyroglobulin -> asymptomatic or transient hyperthyrroidism -> hypothyroidism
goitre will be symmetrically enlarged and painless
pathology: lymphocytic infiltration with germinal centers and hurthle cells
symptoms?
fatigue, depression
cold intolerance
weight gain
hair loss, brittle nails, cold dry skin
bradycardia
constipation
proximal myopathy (progressive muscle weakness)
hypertension and menorrhagia
HYPOREFLEXIA (WOLTMAN SIGN)
generalized myxedema (fluid collection):
myxedematous heart (dilated cardiomyopathy), hoarse voise, pretibial and periorbit edema, myxedema coma
diagnosis?
TFT
subclinical hypothyroid= T4 normal but TSH high
antibodies against thyroglobulin, thyroid peroxidase and TSH receptor
labs: hyperchlorestrolemia, hyperlripidemia, high LDL, low HDL
thyroid scan for nodules
thyroid US for nodules, goitres, and malignancy
treatment? which drugs reduce thyroid hormone?
lifelong levothyroxine with TSH level assessment after 6 weeks. dose is increased in pregnancy.
for subclinical hypothyroidism, only treat when TSH> 10
iron, amiodarone
myxedema coma define, presentation, diagnosis, treatment?
life-threatening worsening hypothyroidism due to stress or non adherance to treatment
present with altered mental status, hypothermia, myxedema, hypoventilation, hypotension
labs: high TSH low T4, T3, hyponatremia, hypoglycemia, low cortisol
tx resuscitate with ABCDE approach
IV levothyroxine + liothyronine + hydrocortisone (can be stopped when adrenal insufficiency is ruled out)
what is euthyroid sick syndrome?
patients who are clinically euthyroid present with a systemic illness that causes low thyroid hormone levels
TSH NORMAL
T3 low and rT3 (reverse) is high
because T4 is converted to rT3 (inactive) instead of T3 (active)
treatment not indicated only focus on systemic illness
