thyroid - underactive Flashcards
bloods hypothyroid
raised TSH but ok T3/4
mx subclinical hypothyroid if TSH >10 + free T4 normal
levothyroxine // if bloods >10 on 2 separate bloods, 3 months apart
mx subclinical hypothyroid if TSH 5.5-10
<65 + symptoms on 2 bloods 3 months apart = levothyroxine // asymptomatic recheck 6months
most common cause primary hypothyroid
autoimmune hashimotos
other causes primary hypothyroid
subacute, riedels, thyroidectomy, iodine deficiency, lithuim or amiodarone
secondary causes hypothyroid
downs, turners, coeliac
bloods primary hypothyroid
TSH = high // free T4 = low
bloods secondary hypothyroid
TSH = low // T4 = low
features hypothyroid
weight gain // always cold // dry skin + hair // non-pitting oedema // constipation // heavy periods
neuro symptoms hypothyroid
hyporeflexua // carpal tunnel
features hashimotos
hypothyroid + goitre
antibodies hashimotos
anti TPO + anti-Tg
conditions assoc with hashimotos
coalic, T1DM, vitligo
what cancer is hashimotos assoc with
MALT lymphoma
features congenital hypothyroid
prolonged jaundice // delayed milestones // short // puffy face, big tongue // hypotonia
how is congenital hypothyroid diagnosed
screened at day 5-7 with heelprick test
pathology Riedel’s thyroiditis
fibrous tissue replaces thyroid parenchyma –> fixed, painless goitre
TFT’s sick euthyroid syndrome
TSH, T4, T3 all low // (TSH can be normal)
causes sick euthyroid syndrome
systemic illness, normally in elderly
mx sick euthyroid syndrome
none
presentation myxoedema coma
hypothyroid –> confusion + hypothermia
mx myoexedema coma
IV levothyroxine + IV fluid + IV steroids // fix U+Es
starting dose hypothyroid
50-100mcg OD
what people should be started on a lower dose of levothyroxine (25mcg)
cardiac disease, severe hypo, 50+
what needs to be checked after changing levothyroxine dose
TFTs 8-12 weeks later
what should happen to levothyoxine in pregnancy
increase by at least 25-50 // double
SE thyroxine
hyperthyroid // reduced bone mineral density // worsening of angina // AF
