The electrolyte concentration is measured in plasma, which normally consists of about 93 percent water and seven percent solids, mostly proteins and fats. This phenomena can be hyperlipidaemia, hyperproteinaemia or obstructive jaundice. Another consideration is a pseudohyponatraemia, which is a laboratory miscalculation of the serum sodium. In these situations, water is drawn from intracellular to the extracellular space, resulting in a lowered serum sodium concentration, but hypertonicity. This can be the result of a hyperglycaemia or exogenous solute (ie, mannitol, intravenous immune globulines). In case of hyponatraemia without hypotonicity, other conditions should be considered. If the patient is euvolaemic secondary adrenal insufficiency and SIADH need to be considered. Hyponatraemia with a high urinary sodium (≥30 mmol/L) and a hypovolaemic state can also be the result of vomiting, but also the use of diuretics or primary adrenal insufficiency. If the patient is hypervolaemic, cardiac failure, liver cirrhosis and nephrotic syndrome needs to be considered. 2Ī hyponatraemia with a low urinary sodium (<30 mmol/L) and a hypovolaemic state can be the result of vomiting, diarrhoea, sequestration of fluid and recently stopped diuretics. If urinary osmolality ≥100 mOs/kg, urinary sodium and assessment of a patients’ volume status are needed. The use of diuretics should always be considered, as it makes urinary sodium and osmolality more difficult to interpret.Īfter confirming a hypotonic (serum osmolality <275 mOsm/kg) hyponatraemia, in absence of ADH activity, the differential diagnosis includes primary polydipsia, tea and toast and beer drinkers hyponatraemia.

Urinary sodium can help determine if sodium loss is renal of non-renal. Urinary osmolality is also necessary and measures ADH activity, which is present when urinary osmolality ≥100 mOs/kg. The first diagnostic steps in hyponatraemia are to confirm a hypo-osmolar hyponatraemia using serum osmolality, this measurement should match the calculated osmolality. Early recognition of this disease is of vital importance, because hypocortisolism is a potentially life threatening condition and presenting symptoms are often non-specific. 1 One of the causes of hyponatraemia is hypocortisolism. The general incidence of hyponatraemia (serum sodium <136 mEq/L) in hospitalised patients is 30% and in 2.6% serum sodium is <124 mEq/L. Hyponatraemia is a common clinical problem with a multifactorial aetiology.

Hyper adrenaline disorder