Nocturia is a condition in which one feels the need to wake up at night and urinate. Medically it is defined as Getting up at night to pass urine more than once, and urination should be associated with sleep both before and after urination. It can occur in both males and females and it becomes more common as people age. There are various reasons associated with it. Primarily it can be over-production or difficulty in retaining the urine produced.