Define about the Hyponatremia and Hypernatremia?
Serum concentration of sodium is normally regulated within the range of 135 to 145 milimole per litre (a). Hyponatremia is defined as a Na level under 130 mM/L. When plasma Na level falls below 120 mM/L, symptoms such as headache, confusion, seizures and coma can occur, Hyponatrernia can arise from shift of water from cells to extracellular compartment, which is induced by an increase in solutes in plasma for example increased plasma glucose in diabetes can result in the shift of water from ICF to ECF, diluting the Na concentration. Hyponatremia is also induced by renal failure when .kidney's impaired ability to excrete waste products results in build up of solutes in plasma. It can also occur from an overall decrease in body, Na, as occurs during diarrhoea and vomiting.
Rare instances of hyponatremic dehydration have been reported in sports persons rehydrated only with water. Hypernatremia occurs less commonly and is defined as serum sodium level above -A 145 mM/L. The initial symptoms include irritability, lethargy and restlessness. Seizures and death may occur when plasma levels rise above 160 mM/L. Hypernatremia occurs with loss of water that is disproportionately greater than sodium and is associated with excessive sweating and hyperventilation. It can also occur when thirst mechanism is impaired because of damage to hypothalamus.