SIADH and hyponatremia

Jan Hudec, MD, Miriam Šipošová, Kristýna Chudjáková

The syndrome of inapropriate secrection of the ADH – antidiuretic hormone develops after injuries, operations or brain infections. Secretions of the ADH in organism results in water retention and also decreasing of plasma sodium level. However there are also other causes of hyponatremia, which differ significantly in their clinical solution. That is why it’s so important for the doctor to find the cause of hyponatremia as soon as possible and suggest correct therapy. This algorithm guides you in differential diagnosis of hyponatremia and folowing possibilities of the therapy.


Ľudmila Trejbalová, MD Senior Physician, 1st Internal Medicine Department, Ludovit Derer University Hospital, Bratislava, Slovakia

Hyponatremia is one of the most common laboratory deviations which can occur in critically ill patients. It is connected with higher morbidity and mortality so it is important to identify the right cause of this condition as fast as possible. This algorithm emphasizes the importance of discovering plasma and urine osmolality level, urine sodium level and also the possibility to consider extracellular plasma volume.  After the correct diagnostic process this algorithm leads through the therapy of hyponatremia with orientation to the therapy of SIADH according to the european guidelines.

SILBERNAGL, S., DESPOPOULOS, A., Gay, R. and , A. (2004). Atlas fyziologie člověka. Praha: Grada.
GANONG, W. (2005). Přehled lékařské fyziologie. Praha: Galén
HAVRÁNEK, J. (2008). Centrální syndrom ztráty soli jako komplikace u pacientky ako komplikace u pacientky s obstrukčním hydrocefalem. [online] Pediatrie pro praxi. Available at: [Accessed 14 Apr. 2018].
JISKRA, J. (2012). Hyponatremie: diagnostický postup a nové léčebné možnosti. [online] Interni medicina. Available at: [Accessed 14 Apr. 2018].
VODIČKA, M. (2018). Hyponatremie: diagnostický postup a nové léčebné možnosti. [online] Neurologie pro praxi. Available at: [Accessed 14 Apr. 2018].

inserted: 1. 7. 2018 | last modified on: 28. 5. 2020