Hyper/hypo thyroid Flashcards
What is the commonest cause of a hypo/hyper thyroid?
Autoimmune thyroid disease
Are primary or secondary causes more common?
Primary
What does subclinical hypothyrodism look like, biochemically?
Normal T3/4 and raised TSH
What hormones are measured for thyroid issues?
TSH
T4
T3
In overt hyperthyroidism, describe the patterns of TSH and T3/4
TSH will be low.
T3/T4 will be high.
TSH low so negative feedback doesn’t turn off
Why is secondary pituitary gland failure different to primary in terms of hormone balance?
If TSH is high then T3/T4 are high e.g in TSHoma.
What is pre-tibial myxoedema?
Non-pitting oedema with discolouration over lateral malleoli.
Associated with Grave’s disease.
In which sex is hypothryoidism more common?
Females
What are the three types of primary hypothryoidism?
Goitrous
Non-goitrous
Self limiting
What kind of drugs can induce a goitrous hypothyroidism?
Amiodarone, stavudine(HIV)
lithium
A deficiency in what mineral can cause hypothyroidism?
Iodine
True or False
Hypothyroidism cannot be placentally transmitted
False.
Antithyroid agents or iodides can be transmitted
What is the main cause of primary goitrous hypothryroidism?
Hashimotos thyroiditis
What is the main cause of primary non- goitrous hypothryroidism?
Atrophic thyroiditis
True or False
Postpartum thyroiditis is transient
True
If Hashimotos thyroiditis is suspected which antibodies are present in blood?
Thyroid Peroxidase Ab
anti-TPO
What would be seen on microscopy with Hashimotos thyroiditis?
T cell infiltrate and inflammation
What signs can be seen on the skin in hypothyroidism?
Pale, cool skin
Hypercarotenaemia
Vitiligo
Pitting oedema
What changes are seen in hair?
Coarse and sparse hair
What CVS changes may be present?
Hyperlipidaemia
Reduced HR
Cardiac dilatation
Pericardial effusion
Is weight gain or weight loss more common in hypothryoidism?
Weight gain
True or False
Macroglossia is a sign of hypothyroidism
True
True or False
Carpal Tunnel syndrome may present in hypothryoidism
True
Which nerve is affected in carpal tunnel syndrome?
Median
What gynae changes may be present in hypothyroidism?
Menorrhagia
Oligo/amenorrhoea
What will the TSH be like in hypothyroidism?
High
What will the T4/3 levels be like in hypothryoidism?
Low
What is macrocytosis?
Large RBC.
MCV >100
What other changes may be seen in bloods?
Elevated CK
Elevated LDL
HYPOnatraemia
HYPERprolactinaemia
True or False
Younger patients with hypothyroidism should be started on lower doses of thyroxine
False.
Younger patients should be started on 50-100 micrograms
How long after starting thyroxine should TSH levels be checked?
2 months.
4 weeks in elderly
When should thyroxine be taken?
Before breakfast
What consideration should be taken regarding thyroxine in pregnancy?
Dose should go up by half
What is a myxoedema coma?
Occurs in severe hypothyroidism.
precipitated by stroke, MI, infection
What signs are common in myxoedema coma?
Hypothyroid, hypoglycaemic, hypothermic, bradycardia
What changes are present on ECG in myxoedema coma?
Low voltage complexes
?heart block
T wave inversion
QT elongation
What respiratory changes would you be worried about in myxoedema coma?
Type 2 resp failure with hypoxia, hypercarbia –> acidosis
What cardiac changes are present in HYPERthryoidism?
Palpitations
AF
What nervous system changes are present in hyperthyroidism?
Irritability
Nervousness
Anxiety
What GI changes are present in hyperthyroidis?
Frequent loose stools
What is the bulging of eyes called?
Exopthalmus
Proptosis
Exorbitism
What changes are present in hair and skin in hyperthyroidism?
Brittle and thinning hair
Fast growing nails
What is the autoimmune causation for hyperthryoidism called?
Graves disease
What age does Graves disease normally affect?
20-50
In which sex is Graves disease more common?
Female
Is there a genetic link in Grave’s disease?
Yes
Which antibody is positive in Graves?
TRAbs
What are the thyroid hormone patterns in Graves?
High T3/4
low TSH
How is the goitre described in Graves?
Smooth
Symmetrical
High uptake
What is chemosis?
Conjuctival swelling
True or False
Smoking is a recommended treatment for proptosis
true
Eye disease may improve
In who does nodular thyroid affect?
Older patients
What are the test results for nodular thyroid disease?
High T3/4
low TSH
Ab neg
Assymetrical goitre w high uptake
Which eponymously annoyingly named condition is a subacute thyroiditis and may be associated with viral symptoms?
De Quervains
What is the treatment for De Quervains?
No treatment. Will resolve in 18 months
When does a thyroid storm occur?
Severe hyperthyroidism
Underlying infection
What are the symptoms of a thyroid storm?
Resp and cardiac collapse
Hyperthermia
Exaggerated reflexes
What is the Tx for thyroid storm?
Lugols iodine steroids PTU B blockers Fluids
How is hyperthyroidism treated?
Carbimazole
Propylthiouracil (PTU)
What drug can be given for the sympathomimetic symptoms?
Beta blockers specifically propanolol
How does radio-iodine work?
Radioactivity destroys thryoid gland over a few weeks and then pee it out.
What precautions need to be taken with radio-iodine?
No sharing bed
Not pregnant
No contact with pregnant women
When is surgery indicated in hyperthroidism?
Only after drugs and radioiodine have failed
In Graves disease which is the best antibody to check?
TSH receptor antibody
When is scintigraphy used?
In hyperthyroid only
What test is done at 5 days after birth?
Guthrie’s test
What is Guthrie’s test for?
Heel prick test to check TSH/ T4
What symptoms would be present in newborns with congenital thyroid disease?
Delayed jaundice
Poor feeding but normal weight gain
Hypotonia
What is cretinism?
Developmental delay due to absence of thyroxine
What is the normal range for TSH?
0.4-4.0
What is the normal range for T3?
9.9-22
What is the normal range for T4?
0.9-2.6
What side effect of carbimazole means the medication must stop?
Agranylocytosis.
What is agranylocytosis and how might it present?
Lack of granulocytes in blood leading to infection
Cough or sore throat
