Dehydration occurs due to imbalance between the fluid intake and fluid output.When output exceeds the intake it leads to dehydration. Along with water,the essential electrolytes are also lost in dehydration. Elderly,heavy exercisers,people in hot and cold climates or persons with any illness related to fluid loss like vomiting, diarrhea etc are more prone to dehydration.Symptoms of dehydration includes dark yellow urine,dry mouth,confusion,dry and scaly skin,reduced sweat etc.To prevent dehydration keep your body hydrated by drinking water and consuming hydrating fruits and vegetables.Also replenish all your lost electrolytes by electrolytes supplements. Limit the intake of alcohol,tea,coffee etc.Seek medical advice if dehydration is severe.