Endocrinology Flashcards
Secondary and tertiary causes of hypothyroidism
Secondary:
Hypopituitarism
Impaired TSH synthesis
Tertiary: Hypothalamic damage (tumours, surgery, radiotherapy)
Causes of hyperthyroidism
Primary (high T3/4, low TSH): Graves disease Toxic multinodular goitre Toxic adenoma Exogenous (iodine excess) Ectopic thyroid tissue Thyroid follicular carcinoma Drugs (amiodarone, lithium) Postpartum
Secondary (high T3/4, high TSH):
TSH-secreting pituitary tumour
Signs and symptoms of insulinoma
Hypos when ordinarily would be fine
Whipple’s triad
CNS and GI phenomena
Presentation of hypothyroidism
CHAMPS
C - change in bowels (constipation)
H - hair loss
A - appetite / weight (decrease in appetite, weight gain)
M - menstruation (increase, menorrhagia)
P - prefers temperature (hot - cold intolerance)
S - skin changes (cold, dry, loss of outer 1/3 eyebrows)
Plus:
Tired, sleepy, lethargic, low mood, hoarse voice, decreased memory/cognition, dementia, myalgia, cramps, weakness, poor libido
Thyroid pathology
Hypothalamus (TRH)->
Anterior pituitary (TSH) ->
Thyroid gland (T3 & T4)
Peripheral conversion of T4 to T3
What is insulinoma?
Benign islet cell tumour, sporadic or MEN
Complications of hyperthyroidism
HF Angina AF Osteoporosis Exophthalmos Gynaecomastia Thyroid storm
Conditions associated with hypothyroidism
Other autoimmune (T1DM, Addison's, PA) Downs and Turners CF Primary biliary cirrhosis Ovarian hyper-stimulation POEMS syndromes Pregnancy problems
Investigations in thyroid disease
T3/4 TSH T3/4 ratio Hyperglycaemia Hypercalcaemia Elevated ALP Leukocytosis Elevated liver enzymes Cortisol raised Thyroid antibodies Radioiodine uptake scans
3 types of thyroid cancer
P, F, M
Papillary (60%) Follicular (25%) Medullary (5%) Lymphoma (5%) Anaplastic (rare)
Management of hyperthyroidism
Decreasing T4->T3 conversion Propranolol - symptomatic relief Potassium perchlorate - used in amiodarone-induced thyrotoxicosis Radioiodine ablation Thyroidectomy
Lumps in the thyroid
Diffuse goitre (endemic, congenital, secondary to goitrogens, acute thyroiditis, physiological, autoimmune
Nodular goitre (multinodular, fibrotic)
Solitary thyroid nodule (cyst, adenoma, malignancy)
Signs of Graves disease
Eye disease: exophthalmos, ophthalmoplegia
Pretibial myxoedema
Thyroid acropachy
Primary causes of hypothyroidism
Hashimotos Primary atrophy hypothyroidism iodine deficiency Post-thyroidectomy/radioiodine Drugs induced (anti-thyroid drugs) Subacute thyroiditis
Classification of hyperlipidaemia
Primary:
Idiopathic
Familial
Secondary: Hypothyroidism Diabetes Renal disease Liver disease Alcohol
Targets of thyroid treatments
Stop hormone synthesis Release Conversion from T4->T3 Control symptoms Control systemic decompensation with supportive therapy
What is a thyroglossal cyst?
Embryological remnant
Fluctuating swelling in/near midline
Moves upwards when patient protrudes tongue (attached to tract of thyroid)
Moves on swallowing (attached to larynx)
Signs and symptoms of hypoglycaemia
Whipple’s triad:
During starvation
Hypoglycaemia
Relieved by sugar
Autonomic/early:
Sweating, anxiety, tremor, palpitations, dizziness
Neuroglycopenic/later:
Confusion, personality changes, drowsiness, visual troubles, seizures, coma
Presentation of hyperthyroidism
CHAMPS
C - change in bowels (diarrhoea) H - hair loss A - appetite / weight M - menstruation P - preferred temperature (heat intolerance) S - skin changes (sweaty, clammy)
Plus:
Overactive, palpitations, tremor, anxious, irritable, labile emotions
Causes of hypoglycaemia
DIABETIC
High insulin:
Increased activity, missed meal, overdose of medication
NONDIABETIC: EXPLAIN Exogenous drugs Pituitary insufficiency Liver failure Addison's Islet cell tumours Non-pancreatic neoplasms Post-prandial - dumping syndrome
Investigations for thyroid lumps
T3 & T4 Thyroid autoantibodies CXR USS thyroid Radionuclide scans FNA and cytology CT/MRI
Subclassfication of hyperlipidaemia
1LP, 2LD, 3 with E, 4 gets more
1 - Familial, LPL deficiency, increased triglycerides
2 - LDL receptor deficiency, increased LDL
3 - ApoE deficiency
4 - VLDL, increased VLDL, pancreatitis
Define hypoglycaemia
<4mmol/L
<2.2 serious
Presentation of hyperlipidaemia
Incidental finding:
Opportunistic shock
Health screening
Investigation of chest pain)
Presentation with clinical sequelae: MI Acute pancreatitis Xanthelasma Corneal arcus Tendon xanthomata
