Hyponatremia is a medical condition that is characterized by low levels of serum sodium in blood. It is termed as an electrolyte disturbance in which the sodium concentration in the serum is lower than normal.
Sodium and water levels in the body are tightly regulated to keep it functioning normally. Sodium concentration is higher in the bloodstream than inside cells. Regulatory mechanisms help control and maintain sodium levels. If the concentration of sodium is too high in the bloodstream, water will leak from cells into the blood stream to try to dilute and lower the sodium concentration. Conversely, if sodium levels in the bloodstream are too low (hyponatremia), water will leave the blood and enter cells, causing them to swell.
The cause can be an underlying disease which restricts body's ability to regulate sodium levels in the body or intake of too much water or high levels of excretion of sodium from the body. In general, hyponatremia occurs only when there is a defect in the kidney's ability to excrete water.
Common symptoms associated with this condition are
Lethargy
Weakness
Confusion
Nausea/vomiting
Seizures
Dullness
Coma
Other findings depend on the underlying cause
