Hi Helen – children generally become dry at night when their body has matured to the point where it can store the amount of urine their kidneys produce or alternatively they learn to wake-up in response to a full bladder. In the meantime there are a few things you can do that will help encourage healthy bladder habits. Ensure your son drinks sufficient water throughout the day – about 1 litre at his age – this needs to be drunk at regular intervals and will help increase his bladder capacity (do not encourage him to hold onto his wee as this can lead to accidents). A diet high in fruit and vegetables is also important as this reduces the chances of constipation, a known contributor to bedwetting. Encourage him to fully empty his bladder just before he goes to bed and avoid foods and drinks high in sugar and caffeine as these can stimulate the kidneys into producing more urine than usual. Sometimes children continue to wet even after introducing these measures – if he continues to wet once he turns 6 then I would certainly think about taking him to your GP for a full assessment. I would also recommend that you use DryNites rather than Pull-Ups, as these are more absorbent and therefore less prone to leakage.