The body maintains a specific concentration of sodium in the body. The causes of low sodium in the body could be dietary, due to medications, or serious diseases. A very low level of sodium in the body is known as hyponatremia and it is can cause serious health problems. Low sodium levels can result due to fluid loss from the body or due to excessive water intake, thereby diluting the concentration of sodium.
Sodium helps to maintain the electrolyte balance in the body, help in the nerve and muscle function and maintain blood pressure. Although dietary restrictions can cause sodium imbalance, it rarely results in hyponatremia unless there is an extreme unbalanced diet, low in salt, is pursued for long periods of time.
Diseases that affect regulation of water (and thus sodium) in the body can cause low sodium levels. Kidney diseases are one such example that causes hyponatremia. Adrenal glands are responsible for secreting a hormone, aldosterone that affects the function of the kidney. Addison’s disease is another cause of low sodium level as it damages the adrenal glands and this result in low levels of aldosterone.
Vasopressin is another hormone involved in sodium regulation, and is regulated by the pituitary gland and hypothalamus. It targets the kidney and it responsible for conserving water in the body, thus diluting sodium concentration. Any disease that causes more production of vasopressin, results in less concentration of sodium in the blood, and this leads to hyponatremia. Sometimes cancer cells also release vasopressin which could contribute to low sodium levels.
Another method to regulate the level of sodium in the body is by using diuretics. This is especially true in older people and with people with high blood pressure. These drugs works by producing more urine, and thus results in sodium loss from the body. If accompanied with an unbalanced low sodium diet, taking diuretics could also result in hyponatremia.
Excessive loss of water and salts from the body due to sweating, accompanied by huge intake of water or abnormal low sodium diet can lead to hyponatremia. Profuse sweating and fluid loss from the body is seen in marathon runners. If not replenished with proper electrolytes, this can also lead to sodium loss from the body and in extreme conditions to hyponatremia.
In some psychological conditions, patients consume large amount of water and could lead to low sodium levels. Extreme diarrhea and vomiting, if not treated properly could also have dire consequences. It is often recommended that after excessive fluid loss from the body, the body should be replenished with a balanced electrolyte solution.