Hypothyroidism Flashcards
Causes of hypothyrodisims
Iodine deficiency
Goitre
Hashimotos - aitoimmune thyroiditis
Iatrogenic - srugery/medications
Transient thryoiditis
Thyroid infiltrative disorders
Congential
Medications that cna cuase hypothryodisim
Amiodarone - acute
Carbimazole - overtreamtent for hyper
Lithium
Radioactive iodine
Symptoms of hypothyrodism
Tired
Weak
Cold
Constipation
Depression
Menstrual irregularities
Thyrpid pain
Signs of hypothryoidism
Hari loss
Dyr skin
Weight gain
Puffy eyes - oedema general aswell
Slow refleces
Bradycardia + diastolic HPTN
Pericardial effusion
HF
Hoarseness of voice - goitre
Paraesthesia - carpal tunnel syndrome or peripheral neuropahty
How does hypothryoidism cause HF
reduced level of thyroid hormone causes the decreased contractility + heart muscle cannot fully relax -> decreased CO-> diastolic dysfunction
What triggers the release of T3 and T4?
TSH
Where is TSH released from?
Anterior pituitary
Where is TRH released from?
Hypothalamus
Pathwya of thyroid hormones
TRH -> TSH -> T3 + T4
What thyroid hormone condition occurs in peripheral tissues?
T4 to more biologically active T3
Primary vs secondary hypothyroidims
Primary - thyroid gland unable to produce T3 and T4
Secondary/central hypothyroidism - insufficient thryoid stimulation due to pituitary or hypothalamic disorder
What are hormone levels ranges in subclincial hypothyroidism?
TSH levels increased
T3/T4 IN NORMAL range
Thyroid levels in overt hypothyroidism
TSH levels above normal reference range
Freee T4 below normal reference range
What are causes of transient thyroiditis?
Viral infection causing subacute (de Quervians) thyroiditis - painful swelling
Post partum - painless inflam autoimmune condition for up to a year
What gene is ass with hashimotos?
HLA DR5
THyroid infiltrative disorders
Amyloidosis
Sarcoidosis
TB
Malignant - lymphoma, thyroid, mets
What is congential hypothyrpoidism?
Absence or underdevleopment of thyroid fland
Ectopuc hypoplastic gland
Absence of enzymes required for hormone synthesis and iodide transfer
Causes of secondary hypothyroidism
Tumours = pituitary adenomas or gliomas
Surgery, radiotherapy, trauma
Pituitary infarction
Sheehand syndrome
INfiltrative disorders - + haemoachromatomas
Isolated TSH deficinecy or inactivity
Idiopathic
Drugs -
Drugs that cause secodnary hypothyroidism
cocaine, dopamine, glucocorticosteroids, metformin
Complications of hypothyroidims - groups
Cardiovascular
Reproductive
Neurological and cognitive
Cardiovascular complciations of hypothyroidism
Dyslipidemia
Metabolic syndrome - insulin resisitance
Coronary heart disease + stroke
Heart failure
Reproducitve/ pregnancy complciations of hypothyroidism
Increased risk of subfertility/infertility
IN pregnenayc:
INcreased risk of miscarriage, anaemia, pre eclampsia, placental abruption, pp haemorrhage, stillbirth
Adverse neonatal outcomes - prem, low birthweiht, resp distress, congenital abnormalities, hypothyrodism, impaired foetal neurocognitive development