most common things that doctors are consulted about, and yet it is quite different from the illnesses about which people consult their doctors.

Every single human being has wet the bed at some time. The astonishing thing is that so many have ceased to do so.

Bed wetters are of two sorts: those who have never learned to go through the night without wetting the bed and those few who have mastered this skill at some time and then lost it again. Every now and then we meet people in their teens who have not achieved control. Apart from this tiny group with some disability, these young people nearly all have the same trouble -- they are deep sleepers with small bladders and large outputs of urine. There is often a strong family history of bed wetting which may be a cause, or, in extreme cases, a physical abnormality of the bladder or of the tubes which affect the passage of urine.

With toilet training, sooner or later, the child has to learn three things: to keep the outlet shut until much more water has collected in the bladder; to recognise the feeling of a full bladder; to empty it "voluntarily'' instead of "involuntarily'', in the right place at the right time, on the potty or toilet.

As they grow and get stronger, most children seem to find the first of these fairly easy to learn. The second is the more difficult and, until they can do this, they cannot do the third. Naturally, nearly all children are dry by day before they are dry by night. It is also the reason why many parents "lift'' their young children and take them to the toilet at intervals during the night.

If bed wetting continues, parents are bound to worry, to be disappointed and sometimes angry, and the more the younger child is likely to be affected by his/her parents feelings. There may well be a physical problem. This is why it is always a good thing to consult your doctor if you are worried about continuous bed wetting.

In the meantime, the greatest help parents can give their child is to remain calm, patient and hopeful, however difficult this may be. Always praise the child for a dry night, and never scold or chastise for a wet night. The more secure and confident a child feels the easier it will be for him/her to learn.

Encouragement is the key to success and, in one way or another, nearly everyone can be helped. It may take time but often there are signs of improvement quite soon. Once a beginning is made, the end is usually in sight.

Valarie Cheape Health Visitor.