Human body contains 70% of total body weight. It is divided in extracellular and intracellular fluid compartment. Potassium and phosphate are the main cation and anion respectively of the cells, while sodium and chloride preponderate in the extracellular fluid.Water and electrolyte imbalance is one of the common conditions in medical emergencies. It is a clinical manifestation of multiple disorders like SIADH, Metabolic ketoacidosis, Ascitis, Ana saraca etc. Researches should be conducted to get easy availability and to conclude the effectiveness of treatment for this particular condition. We can put forth Ayurvedic(Herbal)preparation to overcome from this condition. We can deal this condition under various principles; like under Samanya vishesh siddhanta, Panchabhautic siddhanta, Lok purush nyaya siddhanta etc. Dinacharya and Ritucharya are described for Samyavastha (Equilibrium) of Sharirastha Bhava. Here an attempt has been made to define rationale of Ayurveda in water and electrolyte imbalance.