Water retention occurs because of many reasons; however not all of them are serious. During pregnancy many women experience water retention. It can also occur if you sit for long hours continuously, for example during a long flight.
However, fluid retention (another name by which water retention is commonly referred) can also a symptom of many medical conditions, some of which are serious like heart failure or kidney disease.
Reduce Your Salt Intake
Reduce Intake Of Refined Carbs