thyroid disorders Flashcards
hyperthyroidism clin features
heat intolerance sweating weight loss tachycardia and palpitations hypertension dihorrea insomnia anxiety
what does thryoid hormone do
speeds up cells basal metabolic rate
cell = burns more energy (produces heat)
increases CO
stimulates bone resorption
what is the throid hormone pathway
TRH (hypothalmamus) TSH (ANTerior pit) T3 and T4 release from follicular cells of thyroid gland t4 --> t3 in the peripheries t3 t 4 inhib trh and tsh
symptoms of hyperthyroidism
PRE EXAM weight loss oligomennorhoea sweat palpatations diarrhoe anxiety heat intol tremor
signs of hyperthryoidism
PRE EXAM tachycardia AF lid lag and retraction (so tired pre exam) goitre thin hair palmar erythema (skin remeber) onycholysis exophalamos warm vasodilated peripheries
Causes of hyperthyroidism
graves disease, commonest
toxic multinodular goitre - due to iodine deficency
iodine excess, usually iatrogenic - exogenous
hyperfunctioning thyroid adenoma- TSH also high
thryoiditis
drugs - amioderone induced thyrotoxicosis
Dx of hyperthyroidism
serum TSH and t3 t4
PRIMARY CAUSE = low TSH high T3 T4
SECONDARY CAUSE = High TSH HIGH T3 T4 (secondary = 2 highs)
isoptope uptake scan
thyroid autoantibodies (TSH-receptor antibody)
glucose = high
Graves signs
exophthalmos
graves dermopathy - pretibial myxedema
goitre
Graves disease what is it pathophysiology and causes
autoimmune disease producing TSH-receptor antibodies
mimics TSH stimulating thyroid
this stimulation of thyroid causes hyperplasia and hypertrophy- goitre
retro orbital inflam or extra occualr msucles = exophlamous
pretibial Myxoedema - graves dermopathy
what is graves assos with
other autoimmune diseases
- pernicious anaemia,
type 1 DM,
Addison
Pharmacological treatment of graves disease
Propranolol -B Blocker- symptomatic treatment
Carbimazole -antithyroid - prevents T3/T4 synthesise
Surgical treatment of graves disease
radioidoine therapy
thyroidectomy
Graves disease onset, triggers and prevalence
Childbirth, Stress
more common in women 20-40
affects 2-5% of all women
complications of hyperthyroidism
thyroid storm = severe hypermetabolism = Pyrexia, arrhythmia hypovelemia potentially fatal
heart failure (to keep up with increased demmand from cells)
DM
osteoporosis (t3 t4 causes bone resoprtion)
angina
AF
infertility
Blindness due to opthalmopathy -graves
RF for graves
smoking
complication of surgery for hyperthyroidsm
=thryoidectomy -= hypOthyroidsm
damage reccurent laryngeal nerve - vocal cord paralysis
hypothyroidism and prevalence
underactivity of the thyroid
1% prevalence 9% lifetime risk in women
10F=M
complications of undiagnosed hypothyroidism
in childdren - poor development, slow growth
myxoedema coma - in stressful situ or poorly managed i.e long standing low thyroid hormone in the blood
=alterted conscious state, confusion
cold - hypothermia
assos of hypothyroidism
say same as hyper
addisons
t1dm
pernicous anaemia
inherited = turners, cystic fibrosis
signs of hypothyroidism
BRADYCARDIC Bradycardia Reflexes relax slowly Ascites/anaemia Dry skin/hair Yawning (anaemia) Cold peripheries Ataxia Round puffy (weight gain) Deep voice/defeated demanour = depression Immobile Congestive heart failure
syptoms of hypothry
cold intol *OPP weight gain despite decrease in appetite **OPP mennorrhagia constipation **OPP oedema lethargy depression dry skin and hair myalgia
what do serum bloods show for primary vs secondary hypothyrodi
primary = thryoid gland issue = low t3 t4 high TSH secondary = pit issue = low TSH low t3 t4 (HYPOPITUITARISM)
Causes of hypo thyroid primary
hashimotos thyroiditis primary atrophic hypothyroidism iodine defic post thyroidectomy / radio iodine lithium/amiodarone
causes of secondary hypothryoid
hypopituitarism
what is hashimotos thyroiditsi
Autoimmune disease causing atrophy and regeneration= causes goitre.
presence of TPOAb
and anti TG
Dx of primary hypothrydo
bloods - TSH = low t3 t4 high tsh
FBC - macrocytic anaemia
hypercholesterolaeimia
postive TPO antiboyd in hashimotos
Mx of hypothyroidms
replacement therapy - L-thyroxine (t4 synthetic ) = LEVOTHYROXINE
titrated review at 6weeks
t4 not t3 as longer half life
does amioderone cause hypo or hyperthyroidism
it causes both. anti arrhythmia drug that contains a lot of iodine
thyroid cancer types
papillary (60%)
follicular (25%)
medullary (C-cells) (5%)
lymphoma (5%)
which thyroid cancer most common
papillary
mets of thyroid cancer
BLBL bone liver breast lungs
causes of prim secon tertiary hyperparathyroidsim
primary = due to parathyroid glands = parathyroid adenoma/carcinoma
4 gland hyperplasia
secondary - due to vit d or calcium deficiency - kidney not working so vit d defic (cant activate it) and no stim of ca absorp in gut (Chronic kidney disease)
tertiary - long term secondary - leads to pth hyperplasia = hyperplasia of PT glands, reanl fai.ure
PTH Ca and Phosphate levels in the diff hyperparathyroids
prim = high PTH High Ca low phosphate secondary = high PTH low Ca high phosphate tertiary = ALL high
secondary = kidney screwed so cant activate vit D required for Ca absorp hence low and cant reabsorb Ca or excrete Ph hence high phosphate tertiary = long term secondary = hyperplasia of gland - high calcium
what is the relationship between calcium phosphate and PTH
low calcium = high PTH
PTH stim calcium reabsorp from bone
the kindeys to reabsorb calicum and excrete phosphate and activate vit D(calcitriol)
calctriol – GI tract = increased absorption of Ca
Cfs of primary hyperpaarathyroids
get hypercalcaeimua therefore PSYCHIC MOANS - depression, confusion GROANS - abdo pain, THRONES - constipation, polyuria polydyspia STONES - kidney stones - renal colic BONES - osteoporosis, bone pain fatigue HTN
investigations for primary hyperparathyroidism
Ca increased PTH increased (inapproriate) PO4- Decreased
DEXA scan
xray looks for bone changes
Treatment for primary hyperparathyroidism
surgically remove adenoma (treat the cause)
increase fluid intake
reduce diatary calcium and vit D
(Cincalcet to reduce PTH)
Tx for secondary hyperparathyroidism
vit D and calcium supplements
biphosphonates for bone
Dx of hyperparathyroidism
DEXA bone scan - osteoporosis
24hr urinary calcium excretion in primary
serum PTH Ca Phosphate
