thyroid pathophysiology Flashcards
if thyroid is asymmetrical or nodular what does that indicate?
cancer
what is thyroid disease?
an imbalance in thyroid hormones – hyperthyroidism or thyrotoxicosis
which disease is most prevalent thyroid dysfunction?
graves
what are the sigs of Grave’s disease?
: heat intolerance (moist, warm skin), anxiety, tremor, weight loss (despite increase appetite), tachycardiac >90bpm (reporting palpitations). Eyelid retraction (staring poppy eyes- exophthalmos), eyelid lag, tremor
how does the thyroid feel with graves disease during palpitation?
no specific nodules - feels firm
what is multinodular goitre?
2 or more nodules – usually metabolic but in 10% of cases may be carcinoma or adenoma
what causes eye protrusion in graves?
abnormal deposition in connective tissue
- Eye protrudes – collagen deposits causing eye to move forwards – staring appearance as eyelids are retracted – periorbital puffiness
what point on examination can indicate eye protrusion?
- Sclera visible above and below iris
what are the signs of hypothyroidism?
cold intolerance, cool, dry and coarse skin, fatigue and depression, constipation, low pitched voice, muscle weakness, weight gain, periorbital oedema, puffy face
how do you treat hypothyroidism?
levothyroxine – synthetic T4.
- Start at 1.6ug/kg OD or 25ug daily in older adults with CHF
- Titrate dose as required – monitor TH profile using TFT results (thyroid function test)
what is goitre?
Goitre – lumps/ swelling around neck
what is autoimmune thyroiditis?
hasimotos disease
chronic inflammation of thyroid leading to progressive disease
who is more likely to get autoimmune thyroiditis?
genetic link - more common in women
how might autoimmune thyroiditis present during examination?
- Associated with goitre – firm and rubbery – may be nodular or smooth
what is hyperparathyroidism?
excess of PTH being secreted from parathyroid glands in neck
what is primary hyperparathyroidism?
Primary: most common
- oversecretes PTH despite normal Ca levels then leads to hypercalcaemia
- aetiology: adenomas or hyperplasia
what is secondary hyperparathyroidism?
secondary: disorder in calcium – phosphate bone metabolism
- pathophysiology: in response to low serum Ca as a result of another condition commonly CKD or vitD deficiency
what is tertiary hyperparathyroidism?
prolonged period of secondary hyperparathyroidism
- pathophysiology: in response to chronic PTH secretion, glands become enlarged and hyperplastic and therefore secrete more PTH autonomously. Can lead to hypercalcaemia
primary hyperparathyroidism cases are mainly sporadic, but what are RF?
- post menopausal women
- previous radiation exposure to neck
- taking lithium
- inherited disorders
what conditions are secondary and tertiary hyperparathyroidism linked to?
- secondary and tertiary are linked to conditions that affects calcium metabolism
primary hyperparathyroidism is commonly asymptomatic, but what are common symptoms?
- fatigue
- polyuria and polydipsia
- constipation
- abdo pain
- vomiting
- confusion
- depression
- bone pain
- renal stones
what management options are there available for parathyroidism?
medical: bisphosphonates, cinacalcet
surgical: parathyroidectomy
what is the MOA of cinacalcet?
calcium-sensing receptor agonist: reduces PTH secretion and therefore serum calcium
what do NICE guidelines include for surgical review in parathyroidism?
- symptoms of hypercalcaemia eg thirst, polyuria/ constipation
- end organ disease – renal stones, fragility fractures/ osteoporosis
- corrected calcium level of 2.85mmol/L or greater
