Hyperparathyroidsim Hyperparathyroidism refers to excess secretion of parathyroid hormone. Primary Hyperparathyroidism Primary hyperparathyroidism is caused by the excess secretion of parathyroid hormone (PTH), resulting in hypercalcemia. 85% of cases are due to a parathyroid adenoma. It peaks at 70+ years…
Hypoparathyroidism is caused by deficient or absent parathyroid hormone production. This results in hypocalcemia and hyperphosphatemia. Definition of terms Term Definition Primary hypoparathyroidIsm Reduced PTH secretion due to gland failure Secondary hypoparathyroidism Reduced PTH secretion secondary to radiation, thyroidectomy, parathyroidectomy,…
Primary Hyperaldosteronism (Conn’s Syndrome) Primary hyperaldosteronism is characterised by autonomous excessive secretion of aldosterone by an adrenal adenoma or bilateral adrenal hyperplasia. It commonly presents with resistant hypertension and hypokalemia. Secondary Hyperaldosteronism Secondary hyperaldosteronism is caused by excessive renal production…
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…