Individuals should seek treatment for a sodium deficiency when they have an increased risk of low blood sodium due to a medical condition and show signs and symptoms of low blood sodium, or hyponatremia, according to Mayo Clinic. Hyponatremia produces muscle weakness, confusion, nausea and vomiting, seizures and coma.
Some medical conditions that affect the heart, liver and kidneys can cause hyponatremia, explains Mayo Clinic. People who participate in highly intense activities or who have other risk factors for hyponatremia and experience symptoms should also consult their doctors. Other symptoms of sodium deficiency include headaches, fatigue, loss of energy, restlessness and irritability. Normal sodium levels range between 135 and 145 milliequivalents per liter of sodium. A blood sodium level less than 135 milliequivalents per liter of sodium indicates hyponatremia.