Thyroid Disorders Flashcards
What are the functions of the thyroid?
T3/T4 acts on
Liver: Increase cholesterol reabsorption, synthesis, conversion to bile and fatty oxidation
Adipose: Increase carb absorption and fatty acid release
Heart: Increase HR and Hypertrophy
Bones: Growth and maturation and Reabsorption
Muscles: Increases protein catabolism, glucose utilisation, fatty acid oxidation
Pituitary: reduce TSH secretion, Increase GH
Nervous system - Formation of axon terminal, myelin sheath, synapse production dendrites
What are the different types of hyperthyroidism and how may this show on TFTs
Hyperthyroidism is When you have excess thyroid hormone T3/T4.
can be either:
Primary (Non-TSH Related) - Graves disease (Autoimmune), Drug induced (amiodarone), Dequrevains Thyroiditis, toxic multinodular goitre TMG, Excess Iodine
TSH - Low ————– T3/T4 - High
Secondary (TSH Related) - Pituitary adenoma
TSH - High ————– T3/T4 - High
Sx of hyperthyroidism
Hyperthyroidism Sx - Everything goes fast
Tachycardia
Sweating
Wt Loss
Palpitations
Nausea
Oligomenorrhea - irregular/infrequent periods
Diarrheal
Intolerance to heat
fever
Tremor
Restless/Yawning
Muscle wasting
goitre
hyperreflix
palmar erythema
Graves specific symptoms
+ Graves Specific Sx
Thyroid acropachy - finger clubbing/swell
Thyroid eye disease (25-50%):
Eyelid retraction
preorbital swelling
proptosis/exopthlamos
Pretibial myxoedema
What are the pathological factors in Graves disease?
Autoimmune antibodies —IgG TSH-R Ab
Anti-TPO
Investigating Hyperthyroidism?
Thyroid Function test:
Primary: TSH - Down, T3T4 - High
Secondary: TSH - High, T3T4 - Low
Serology - Anti-TSH-r, Anti-TPO
IF THYROID IS PALPABLE - Thyroid US - either TMG or Graves
Treating Hyperthyroidism
1st- Carbimazole (sore throat) + Propanolol CI - pregnant Propylthiouracil
2nd- Radioiodine (Definitve tx)
3rd- Thyroidectomy
If Patient presenting w/ eye symptoms - + Corticosteroid
What is an acute complication of hyperthyroidism and what instigates?
Thyroid storm
Systemic decompensation following trauma / infections
= excess T4/T3 Thyrotoxicosis;
Abdo pain
Altered mental status: Confusion/comatose
Jaundice
Signs
Hyperpyrexia very high >40
Tachycardia +/- Atrial Fibb
Reduced GCS
What long term complications present in hyperthyroid diseases
Osteoporosis
Cardiovascular - A fibb / HF
Hyperthyroidism epidemiology
Mainly young women 20-40 yrs (F > M 9:1)
Graves’ disease = 65-75% of cases
Mechanism of action of carbimazole
Blocks synthesis of T4
Thyroid storm TX
Carbimazole/CI Propylthiouracil
After
Logol’s Solution - oral aqueous iodine
IV hydrocortisone
Define Hypothyroidism and causes
Decreased level of circulating thyroid hormones
Primary causes:
Hashimoto’s (Anti-TPO / Anti-TSHr)
iodine deficicency
Drugs -Lithium
TSH - Normal T3/T4 - Low
Secondary causes - Hypopituitarism (requires urgent referral)
TSH - Low, T3/T4 - Low
How may hypothyroidism present
Slows down everything
Hyporeflexia
Round face
Ascites
Dry hair/Skin
Ataxia
Yawning
Brad cardiac
\cold intolerance
Agitated
Weight gain
Menorrhagia
Constipation / Loss of appetite
Investigating Hypothyroidism
Thyroid functions test
+
Serology - Anti-tpo / Anti-TSHR
What is hyporthyroidism associated with
perncious anemia
LOW T4 Tx
Levothyroxine (T4)
+
Ferrous sulphate
What different types of thyroid cancers are there
Papillary MC
Follicular
Anaplastic - Mosr sever
Medullary
Where do thyroid cancer metastases to?
Lungs
Bone
Liver
Brain
How do thyroid cancer present
Usually euthyroid = no hyper/hypo sx
Cancer signs - wtloss/ fatigue/ night sweats
+
Local pressure on trachea - hoarsness / deviation
How to treat thyroid cancer?
Thyroidectomy + Lifelong levothyroxine
Radioiodine ablation
If its anaplastic - palliative care
Thyroid cancer IVX
TFTS
Neck/thyroid US
Thyroid fine needle biopsy
When is radioiodine contraindicated?
