Phaeochromocytoma is a neuroendocrine tumour that arises from chromaffin cells of the adrenal medulla. It is characterised by excessive catecholamine production, which causes the clinical triad of headache, diaphoresis, and tachycardia. 10% occur in children, 10% are bilateral, 10% are…
The overproduction of prolactin causes hyperprolactinaemia. It is the most common hormonal disturbance of the pituitary gland. It is present early in women due to menstrual disturbance. Prolactin levels > 5000 are likely to be due to a prolactinoma. Macroadenomas (>…
Acromegaly is caused by excessive secretion of growth hormone. It is characterised by progressive enlargement of the hands, feet, and face, as well as systemic complications. Excess growth hormone in children causes gigantism due to long bone growth since the…
Diabetes insipidus is an inability to concentrate urine due to a lack of antidiuretic hormone (ADH) or insensitivity to ADH in the kidneys. Classification of diabetes inspidus Classification Description Causes Central diabetes insipidus Reduced secretion of ADH by the posterior…
Syndrome of inappropriate antidiuretic hormone (SIADH) is caused by excessive antidiuretic hormone (ADH) production despite low plasma osmolality or large plasma volume. It is characterised by euvolemic hyponatremia – dilutional hyponatremia with no evidence of extracellular fluid overload. The diagnosis…
Thyroid eye disease affects 25 – 50% of patients with Graves’ disease. Severe thyroid eye disease is not related to the degree of thyrotoxicosis
Antithyroid Drugs Drug Action Propylthiouracil (PTU) Inhibits thyroid peroxidase and blocks iodine organification. Also inhibits the peripheral conversion of T4 to T3 Methimazole Large doses of steroids inhibit the peripheral conversion of T4 to T3 and inhibit hormone production Beta-blockers…
Myxoedema coma is an extreme form of hypothyroidism that has a high mortality. It is rare, but it can occur in patients with undiagnosed or undertreated hypothyroidism.
Thyroid storm is a life-threatening, severe physiologic reaction to uncontrolled hyperthyroidism.
Subclinical hyperthyroidism occurs in an asymptomatic patient with normal T4 and T3.