Nocturia, defined as waking at night to pass urine, is a common condition which increases with age. Whilst nocturia is known to have an important effect on quality of life, more recent evidence has linked the symptom with significant morbidity and mortality due to the effects of sleep deprivation on glucose metabolism and the immune system. The causes of nocturia are multifactorial and may be related to urine overproduction, storage disorders and primary sleep disorders. The commonest underlying pathology, however, is nocturnal polyuria, which may be associated with a number of medical conditions. This review explores the underlying causes of nocturia and nocturnal polyuria and, by doing so, describes a multidisciplinary approach to managing patients effectively.