Final answer:
The patient is being treated for hyponatremia, characterized by low sodium concentration in the blood, with diuretics, sodium restriction, and balance of fluid intake using isotonic saline or hypotonic fluids.
Step-by-step explanation:
The patient appears to be treated for hyponatremia, which is a lower-than-normal concentration of sodium in the blood. Treatment includes the use of diuretics to remove excess water diluting the sodium, sodium restriction to prevent further dilution of sodium levels, and the administration of isotonic (0.9% NaCl) normal saline or hypotonic (0.45% NaCl) fluids to correctly balance the sodium levels. The management of body fluids in such cases is vital since an imbalance can lead to symptoms ranging from lethargy and confusion to seizures or coma.