L34 Clinical investigations & presentations Flashcards
(34 cards)
how prevalent is hyperthyroidism in the female population?
2 %
10 times more common in women
how is T3 and T4 secreted?
hypothalamus secretes releasing hormone, TRH which stims ant pit to secrete a trophic hormone, TSH, which stims thyroid to secrete T3 and T4
What are the 5 types of hyperthyroidism?
Graves’ Disease autoimmune condition (80%)
toxic nodule or toxic MNG (15%)
thyroiditis (1%)
drug induced eg amiodarone which is used to treat irregular heartbeat (40% of drug is iodine)
rarities (other)
how does toxic nodule/toxic MNG and thyroiditis cause hyperthyroidism?
Toxic nodule/toxic Multinodular groitre - nodule/s in the thyroid that work independently from thyroid and overproduce the hormones
thyroiditis - Destruction of thyroid gland which releases thyroid hormones. Go from being overactive to underactive as the thyroid is not making hormones. Then cells recover
What causes Graves’ Disease?
the body produced antibodies that work similarly to TSH. it binds to the TSH receptor which promotes the production of T3 and T4
what are the clinical presentations of Graves’ Disease?
Hyperactivity, irritability, insomnia
Heat intolerance and increased sweating
Palpitations
Weight loss despite overeating
Menstrual problems
how do you examine for hyperthyroidism?
check for Signs of thyrotoxicosis:
- Hand tremor
- Increased sweating
- Fast pulse
Inspection of the thyroid:
- Enlarged (usually)
- Smooth: Graves’ disease
- Nodular: toxic nodule(s)
- Tender: thyroid inflammation
can also percuss around the chest area and check for difficulty in breathing/ swallowing
how do you feel for the thyroid/ anatomy?
three fingers with the pads of the fingers. first feel for the adam’s apply. south of here feel for the cricoid cartilage. feeling laterally from here is the thyroid. asking the patient to swallow should cause the thyroid to move up and down.
is supplied by the superior and inferior thyroid arteries. common carotid artery passes laterally to the lobes of the thyroid and the larynx lays superior to the gland
which extrathryoidal signs of thyroid eye disease may accompany hyperthyroidism?
swelling around eyes - periorbital oedema
protrusion of the eye ball - proptosis
paralysis of the eye muscles
what would you look for in a blood test to diagnose hyperthyroidism?
raised T3 and T4
suppressed TSH
(static test is enough)
what are the treatments for hyperthyroidism?
anti-thyroid drugs - disease remission in 50% of patients after 6-18 mo of treatment. but can suppress WBC so more susceptible to infection - dangerous!
radioactive iodine - thyroid picks up the iodine which destroys the gland, leading to underactive thyroid. then just treat with thyroid replacement hormones - no side effects
surgery - removing some of the gland
what a deficiency in growth hormone cause in children and adults?
children - failure of growth
adults - sometimes nothing. sometimes tiredness, fatigue, depression
is a static test enough to test for growth hormone deficiency?
no, a stimulation test is required.
glucagon stimulation test (safer) = glucagon is injected. GH levels should increase
insulin stress test (less safe) = lowers blood glucose, stressing the body and forcing growth hormone secretion
how do you treat for growth hormone deficiency?
growth hormone injections - expensive and usually reserved for children with the deficiency.
check symptoms in adults. if no symptoms = dont treat. if symptoms are not getting better with injections, stop treatment
what may be the causes of steroid undersecretion?
adrenal failure
pituitary failure
what are the clinical presentations for steroid undersecretion?
Failure to grow in children
Severe tiredness
Dizziness due to low blood pressure
Abdominal pain, vomiting an diarrhoea
how can you test for steroid undersecretion?
synacthen test (giving ACTH) if primary adrenal failure is suspected. should stim rels of glucorticoids eg cortisol. check after 30 min
Glucose stimualtion test GST or insulin stress test IST if secondary adrenal insufficiency is suspected
how do you treat steroid hormone undersecretion?
replace the missing hormone with tablets - cheap
if steroid undersecretion diagnosis is suspected, give cortisol before receiving blood results. could die from too little, too much will not kill
why should patients be weaned off steroids, rather than stopping them all at once?
adrenal glands need time to recover. stopping abruptly could cause adrenal crisis
what is the difference between primary and secondary hypothyroidism?
primary - thyroid failure ans inability to produce thyroid hormones (common). - usually autoimmune in nature but Can be drug induced eg amiodarone
Secondary hypothyroidism: failure to produce TSH (rare). - Usually part of complete pituitary failure
both very common in older ladies
what are the signs and symptoms of severe hypothyroidism?
Weakness and dry skin >95%
Sensation of cold and decreased sweating 80%
Impaired memory 65%
Constipation 60%
Weight gain 60%
Hair loss 60%
how is hypothyroidism diagnosed and treated?
diagnose with a static test of thyroid function (expect low T3 and T4 but high TSH)
treat with thyroid hormone replacement tablets (cheap)
constipation is caused in hyper/hypothyroidism and hyper/hypocalcaemia? true/false
false. constipation is caused in hypercalcaemia and hypothyroidism
how does sex hormone deficiency present?
males
- erectile dysfunction
- reduced libido
females
- menstrual abnormalities eg amenorrhoea
