Thyroid Dysfunction Flashcards
what is a goitre
enlargement of the thyroid gland when it is over stimulated
what is hypothyroidism
when the thyroid gland is not producing enough of the thyroid hormones
what are symptoms of hypothyroidism
obesity, bradycardia, hoarse voice, slow reflexes, tiredness, cold intolerance, menorrhagia, puffy face/hands/feet, loss of outer 1/3 eyebrow, non pitting oedema
what happens to the TSH levels in hypothyroidism
they increase
what causes hypothyroidism
TSH/TRH deficiency inadequate iodine autoimmunity congenital surgical removal of thyroid gland
what condition is seen in children with hypothyroidism and what are the features of this
cretinism - dwarfed statue, mental deficiency, poor bone development, slow pulse, muscle weakness
what condition is seen in adults with hypothyroidism and what are the features of this
myxedema - thick puffy skin, muscle weakness, slow speech, mental deterioration, intolerance to cold
what is the autoimmune disease causing hypothyroidism and what are the treatments
Hashimoto’s disease
treatment = oral thyroid hormone
what is the autoimmune disease causing hyperthyroidism
Graves’ disease
what causes hyperthyroidism
- autoimmune
- toxic multinodular goitre
- drugs
- thyroid carcinoma
what are the symptoms of hyperthyroidism
weight loss, heat intolerance, tachycardia, weakness, increased appetite, hyper reflexive, amenorrhea, tiredness, warm sweaty hands, bounding pulse, lid lag, staring eyes
how does Graves’ disease work
causes the production of thyroid stimulating immunoglobulin which stimulates thyroid hormone secretion
what happens to the TSH levels in hyperthyroidism
decrease
what radioisotope is used to scan the thyroid gland
technetium 99
what drug is used to treat overactive thyroid
carbimazole
what does carbimazole do
its a pro drug which is converted into methimazole in the body which prevents thyroid peroxidase from coupling the iodinating tyrosines on the thyroglobulin
what is lingual thyroid
where part of the thyroid gland stays on the tongue as it didn’t migrate down during development
why does a thyroglossal duct cyst form
when not all of the thyroglossal duct disappears during development
where are thyroglossal duct cysts found
on the anterior part of the neck in the midline
what causes the thyroglossal cyst to move upwards
tongue protrusion
what is an adenoma
benign tumour of the glandular epithelia tissue
what causes the majority of thyroid diseases
primary abnormality of the thyroid gland itself
why is there such a wide range for normal thyroid hormone levels
the hypothalamus is constantly responding to the changes in the environment
what 3 classifications of goitres are there
- diffuse (affecting the whole thyroid)
- multinodular
- single nodule
in which gender are goitres more prevalent in
females
what is a physiological goitre
swelling of the thyroid gland however there is still normal thyroid function
what is the most common cause globally of goitre
iodine deficiency - the reduced thyroxine levels leads to increased TSH leading to thyroid enlargement (usually nodular)
in which areas is iodine deficiency seen
mountainous areas (as theres iodine in the sea)
what is the most common cause of goitre in the uk
Multinodular goitre where the cause is unknown. It may cause hyperthyroidism making it a toxic multinodular goitre
what happens to the child if the mother is iodine deficient in pregnancy
the child may develop mental retardation, abnormal gait, short statue, goitre and hypothyrodism
what is a retrosternal multinodular goitre
where a multinodular goitre enlarges inferiorly compressing the trachea
what is thyrotoxicosis
excessive amount of thyroid hormones
what is lid lag
delay of moving the eyelid down as the eye moves down
what is staring eye
when the levator palpebrae superioris muscle is constantly stimulated due to the increased sympathetic stimulation
what causes hyperthyroidism
- autoimmune
- toxic multinodular goitre
- toxic adenoma
what is seen in graves disease
Exopthalmos (bulging of the eyes)
Pre-tibial myxoedema
what is myxoedema
non pitting oedema due to depositions of mucopolysaccharides
how does a toxic adenoma cause hyperthyroidism
the adenoma can independently produce thyroxine
what are the treatments for hyperthyroidism
- carbimazole
- thyroidectomy
- radioactive iodine
true or false: thyroid cancers cause hypothyroidism
false - they do not cause either hypo or hyper
what 3 causes of goitres have no metabolic affects
- thyroid cancer
- iodine deficiency
- multinodular goitre
what 4 causes of a goitre also cause metabolic dysfunction
- graves
- hashimotos
- toxic adenoma
- toxic multinodular goitre
