Hyperthyroidism Flashcards
what is the definition of hyperthyroidism?
overproduction of thyroid hormone
what is the epidemiology of hyperthyroidism?
2.5% prevalence, endemic in iodine deficient areas. Affects 2-5% of all women at some time, Mainly between 20-40yrs
what is the aetiology of hyperthyroidism?
- Graves’ disease - MOST COMMON CAUSE
- Toxic multi nodular goitre
- Toxic adenoma (benign)
- Ectopic thyroid tissue (metastases)
- Exogenous (iodine/T4 excess)
- De quervain’s thyroiditis (post-viral)
what are the risk factors of hyperthyroidism?
Female, smoking, stress, high iodine intake, autoimmune diseases
what is the brief pathophysiology of hyperthyroidism?
Hyperthyroidism may result from increased synthesis and secretion of thyroid hormones (thyroxine [T4] and triiodothyronine [T3]) from the thyroid, caused by thyroid stimulators in the blood or by autonomous thyroid hyperfunction. It can also result from excessive release of thyroid hormone from the thyroid without increased synthesis. Such release is commonly caused by the destructive changes of various types of thyroiditis. Various clinical syndromes also cause hyperthyroidism.
what are the key presentation of hyperthyroidism?
Most likely mild. Fever, tachycardia, goitre, muscle wasting, hoarse voice, breathless, agitation
what are the signs of hyperthyroidism?
Agitation, fine tremor, warm moist skin, palmar erythema.
Sinus tachycardia, atrial fibrillation, heart failure, peripheral oedema.
Thyroid enlargement (a goitre)
Pruritus, urticaria, vitiligo, diffuse alopecia.
Muscle wasting, proximal myopathy, hyper-reflexia.
Splenomegaly, lymphadenopathy.
Gynaecomastia in men.
Extrathyroid manifestations of Graves’ disease
what are the symptoms of hyperthyroidism?
Rapid-onset malaise, fever, and thyroid pain (may suggest subacute thyroiditis).
Compression symptoms of breathlessness, hoarse voice, dysphagia, neck pressure (may be caused by a toxic multinodular goitre).
Agitation, emotional lability, insomnia, irritability, anxiety, palpitations.
Exercise intolerance, fatigue, muscle weakness.Heat intolerance, increased sweating.
Increased appetite with unintentional weight loss, diarrhoea.
Subfertility, oligomenorrhoea, amenorrhoea.
Polyuria, thirst, generalized itch.
Reduced libido, gynaecomastia in men.
Deterioration in blood glucose control and hyperglycaemia in people with diabetes mellitus.
Deterioration of co-morbid heart disease, for example in the elderly.
what are the first line investigations for hyperthyroidism?
Thyroid function blood tests, Possible signs or complications of hyperthyroidism, including assessment of pulse, blood pressure, temperature, weight, signs of fluid overload or heart failure.
what are the gold standard investigations for hyperthyroidism?
A hard and irregular goitre or nodule may indicate malignancy.
recognition and referral for more information on urgent management.
Signs of Graves’ disease, including orbitopathy.
Signs of other autoimmune diseases such as type 1 diabetes mellitus and vitiligo.
Suspect a diagnosis of overt hyperthyroidism if the TSH level is low and FT4 and/or FT3 levels are raised above the normal reference ranges.
Suspect a diagnosis of subclinical hyperthyroidism if the TSH level is below the normal reference range and FT3 and FT4 levels are within the normal reference range.
what other investigations should be done for hyperthyroidism?
Consider checking additional blood tests
what are the differential diagnoses for hyperthyroidism?
Graves disease, painless thyroiditis, or factitious hyperthyroidism
how is hyperthyroidism managed?
Arrange emergency admission if there are symptoms suggesting a serious complication, such as thyrotoxic crisis.
Arrange urgent referral to an endocrinologist for specialist assessment if a pituitary or hypothalamic disorder is suspected, depending on clinical judgement.
Arrange referral or discuss with an endocrinologist the need for specialist investigations and management,
Consider prescribing a beta-blocker and titrating the dose depending on clinical response, to provide relief of adrenergic symptoms (such as palpitations, tremor, tachycardia, or anxiety).
Consider seeking specialist advice about starting antithyroid drugs such as carbimazole in primary care for people:
how is hyperthyroidism monitored?
Clinical and laboratory monitoring should be stepped up (monitor TSH, FT4 and FT3 every two to three months until TSH values return to normal). – Increased FT4 and FT3 values indicate overt hyperthyroidism.
what are the complications of hyperthyroidism?
Graves’ orbitopathy, thyrotoxic crisis, compression symptoms, musculoskeletal problems, cardiovascular problems, osteoporosis, mortality
