Hypernatremia is an elevated serum sodium level. It is commonly caused by sodium gain or water loss exceeding sodium loss. Classification of hypernatremia Category Description Hypovolaemic hypernatremia Gastrointestinal losses – diarrhea, vomiting, or fistulas; renal losses – diabetes inspidus; cutaneous…
Hyponatremia is a low serum sodium concentration. Classification of hyponatremia Category Causes Nota bene Hypovolemic hyponatremia Gastrointestinal losses – diarrhoea and vomiting; renal losses – diuretic overuse and mineralocorticoid deficiency; cutaneous losses – burns and sweating; third spacing of fluid…
Osmotic demyelination syndrome (central pontine myelinolysis) can occur due to overcorrection of severe hyponatremia.
Hyperkalaemia is a serum potassium concentration above the reference range. Severity K+ concentration (mEq/L) EKG progression Mild hyperkalaemia 5.5 – 6.5 Peaked T waves and prolonged PR segment Moderate hyperkalaemia 6.6 – 7.5 Loss of P wave, prolonged QRS complex,…
Hypokalaemia is a serum potassium concentration below the reference range.
Hypercalcaemia is characterised by an elevated concentration of serum calcium above the normal range. It is commonly caused by primary hyperparathyroidism or malignancy. Classification of hypercalcemia Classification Description Primary hypercalcaemia Commonly due to primary hyperparathyroidism or malignancy – breast cancer,…
Hypocalcaemia is characterised by a decreased level of calcium in the bloodstream. It is commonly caused by hypoparathyroidism or vitamin D deficiency. Acute hypocalcemia is a medical emergency that requires prompt correction with intravenous calcium gluconate. Causes of hypocalcaemia Category…
Hypopituitarism is characterised by reduced secretion of anterior pituitary hormones. Panhypopituitarism is a deficiency of all anterior hormones. It is commonly caused by surgery, a pituitary tumour, and radiation. Hormones are affected in this order: Growth hormone (GH) → Luteinizing…
Hypopituitary coma is a decompensation of chronic hypophyseal failure that is characterised by hypothermia, refractory hypotension, and signs of hypopituitarism.
Hypercortisolism is caused by excessive glucocorticoids. Definition of terms Term Definition Cushing’s syndrome The clinical state that is produced by chronic glucocorticoid excess, loss of the hypothalamo-pituitary-adrenal axis, and loss of circadian rhythm of cortisol secretion. Exogenous hypercortisolism Hypercortisolism caused…