Dehydration occurs when the body loses more water than it gains, mostly from the intracellular volume (ICV). Low-intake dehydration is the consequence of consuming insufficient amounts of pure water, which increases the osmolality of both compartments and resulting in the loss of intracellular and extracellular fluid. Clinically, volume depletion affects the interstitial compartment and is brought on by excessive losses of fluid and salt, especially sodium and occasionally other elements. The main cause of the fluid loss is a decrease in extracellular volume (ECV); the serum osmolality will either be low or normal. From a physiological standpoint, it makes sense that many clinicians refer to any loss of total body water as dehydration in their routine clinical practice. Most people who have mild to moderate dehydration as a result of vomiting, diarrhoea, or fever can recover by drinking more liquids, such water. Full-strength fruit juice and soft drinks might make diarrhoea worse. If you work outside or exercise in hot or muggy weather, your best bet is cool water. The best way to treat dehydration is to replenish the body with enough of fluids, such as water, diluted squash, or diluted fruit juice. A salty snack can help you replace lost salt, while a sweet drink can help you replace lost sugar. We go over the causes, prevalence, accessible therapies, and present state of dehydration in this review study.