Risk factors & causes
Primary Nocturnal Enuresis -:
- A family history of nocturnal enuresis in close relatives. Epidemiological studies show that if one parent has a history of nocturnal enuresis the children are 5-7 times more likely to have the disorder.
- Delayed bladder maturation. The high spontaneous resolution rate of nocturnal enuresis implies a role for delayed maturation of a normal development process. Many children overcome enuresis naturally – without treatment as they grow older. The number of cases of enuresis goes down by 15% for each year after the age of 5 years.
- Small capacity bladder. Children with nocturnal enuresis have been noted to have a smaller bladder capacity than age matched children who do not have nocturnal enuresis
- Decreased nocturnal anti-diuretic hormone (ADH) secretion and polyuria. Some children with nocturnal enuresis have decreased nocturnal secretion of ADH and increased urine production at night. ADH is a hormone produced in the posterior pituitary gland of the brain. It stimulates renal (kidney) retention of water. Decreased nocturnal ADH secretion would mean the kidneys retained less water and so more urine was produced (polyuria). Since ADH secretion is thought to increase with bladder distension, small bladder capacity may contribute to the decreased nocturnal ADH secretion.
- Sleep disorders are associated with nocturnal enuresis.
- Bladder instability. Some children with nocturnal enuresis have detrusor (bladder muscle) instability. This means the bladder involuntarily empties partly or fully before the child is fully aware of the need to pass urine or to find a toilet. This is often accompanied by a small volume bladder and frequently symptoms of daytime urgency, frequency or daytime enuresis.
Secondary Nocturnal Enuresis -:
- An extremely important cause of secondary enuresis is emotional upset e.g. parental separation or illness, bullying at school or sexual abuse etc.
- Other causes of secondary enuresis include cystitis (urinary tract infection) and constipation, both of which reduce bladder capacity, diabetes (if not treated), which increases the volume of urine produced and some drugs.
