Enuresis is the medical term for what is commonly known as bedwetting. It is quite common during childhood, and is more common in boys than in girls. Bedwetting is not caused by taking too much fluid before going to bed, or by mental or behavioural problems, but by other causes: genetic factors, difficulty waking up, urinary tract infections, and slow development of the central nervous system, among others. Childhood nocturnal enuresis can occur because the child's bladder is still too small; also because the amount of urine produced at night is greater than the bladder can hold, or simply because it takes more time to learn to control this organ. As for treatment, bladder medications are generally used to retain more urine only when previous behavioural therapy has not worked.