Thyroid disorders Flashcards
Sx of Hyperthyroidism?
Hands:
- fine tremor
- brittle skin/hair
Eyes:
- lip lag
- lid retraction
- GRAVES (exopthalmosis, oedema)
Neck:
- goitre smooth diffue
- nodular - Toxic multinodular goitre
Cardiac:
- tachy arrhythmias
- palpitations
- HTN
Abdo:
- Diarrhoea
- weight loss w/ increased appetite
Urogenital:
- women - irregular/stopped periods
- men - ED, decreased ibido, infertility
MSK:
-proximal muscle weakness
You test TSH, Free T4 and total T3 for a patient with query hyperthyroidism, what results would you expect for subclinical or overt hyperthyroidism?
Subclinical:
- TSH - low
- T4 normal
- T3 normal
Overt:
- TSH - low
- T4 - high
- T3 - high
What other tests can you do for a suspected hyperthyroidism?
- thyroid antibodies
- Radioactive iodine uptake test
- thyroid USS
- thyroid biopsy
What are the many causes of hyperthyroidism?
Hyperfunctioning thyroid
- Graves (most common)
- Toxic multinodular goitre
- toxic adenoma DEde
- ectopic T4 production
Inflamed thyroid
- De Quervains thyroiditis (subacute, post viral URTI)
- drug induced (amiodarone, lithium)
- hashimoto’s thyroiditis
Management of hyperthyroidism?
- Sx control - propanolol, if C/I CCB verapamil
- anti-thyroid drugs - carbimazole
- radioactive iodine ablation
- surgery to remove any nodules
Tell me about Graves
- Autoimmune T cell mediated antibodies against TSH receptors that causes an increase production of T4
- associated with other autoimmune diseases such as T1DM, pernicious anaemia, MG
- Can be triggered by infection, stress (physical and psychological), pregnancy, environmental factors (smoking, irradiation, drugs)
- TSH receptor (TRAbs), anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (anti-TG) antibodies
Tell me about toxic multinodular goitre (TMN)
- chronic iodine deficiency causes over stimulation of the thyroid
- common in females >60 y.o.
- multiple painless nodules felt in the goitre
- Tx - radial thyroidectomy
What is a thyroid storm? what are it’s symptoms? How do you treat it?
- acute exacerbation of hyperthyroidism that leads to a life threatening hypermetabolic state
- hyperpyrexia (sweating), hypotension, tachycardia
- severe N&V/diarrhoea
- severe MH disturbances - anxiety, depression, psychoses
How do you treat a thyroid storm/crisis/thyrotoicosis?
- propylthiouracil
- potassium iodide (large intake of Iodine stops T4 production for 5-10/7)
- propranolol
- consider ITU support early
What are the causes of hypothyroidism?
-congenital - hypothyroidism
acquired:
- primary - reduced T4 & 3 production - hashimoto’s, deQuervain, pregnancy
- secondary - reduced TSH - adenoma
- tertiary - reduced hypothalamic action
What’s the difference between primary, secondary and tertiary hypothyroidism? How do you tell them apart?
- primary = thyroid problem
- secondary = pituitary problem
- tertiary = hypothalamus problem
TSH is high in primary
TSH is low on secondary + tertiary
How do you treat hypothyroidism?
-levothyroxine 50-100mcg
In which group of patients should you change the staring dose of levothyroxine?
- Patients with cardiac disease, severe hypothyroidism and patients over 50
- should be started at a lower dose and titrated up slowly
What are the side effects of being treated for hypothyroidism?
- hyperthyroidism
- lowering of bone mineral density
- worsening of angina
- AF
At what levels of TSH should one watch and wait OR treat even if they’re symptomatic?
- 4-10 watch and wait >80
- 4-10 <80 an trial levo but stop if no Sx improvement
- > 10 treat with levo regardless
