It is a common electrolyte disorder. It refers to a low sodium concentration in the blood or salt deficiency. It is generally defined as a sodium concentration of less than 135mmol/L. Sodium is an essential electrolyte that helps maintain the balance of water in and around the cells. Besides maintenance of fluid balance, sodium is essential for many body functions such as regulation of blood pressure and for proper functioning of the muscle and nervous system.
Hyponatremia may result from excess fluid in the body relative to a normal amount of sodium, or it may be due to a loss of sodium and body fluid caused by chronic conditions like kidney or congestive heart failure. Hyponatremia has sometimes been referred to as “water intoxication” especially when it is due to the consumption of excess water, for e.g. during strenuous exercise without adequate replacement of sodium. The symptoms of this disorder may vary from mild to severe. Mild symptoms include weakness, fatigue, headache, nausea, vomiting, muscle cramps, confusion etc. In acute hyponatremia, sodium levels may drop rapidly resulting in potentially dangerous effects such as rapid brain swelling, which can result in coma or death. A basic metabolic panel tests measures the amount of electrolytes and minerals in the blood which may identify low blood sodium level. Treatment basically includes medications, cutting back on fluid intake and infusing intravenous sodium solution.