Are there things that can bring on or prevent relapses?

This question excites a lot of interest but the answers are seldom clear-cut. There is not always enough information available and research has not yet established what triggers a relapse. Often, common sense has to prevail.

There have long been concerns that factors such as trauma (including surgery), stress, vaccinations and infections may increase the likelihood of having a relapse. Studies in these areas are difficult but the evidence we have does not indicate that trauma or stress make a relapse more likely to happen.

Infections are more complicated and it would seem that they may make an attack more likely. For this reason, people with MS are encouraged to treat infections (such as bladder or chest infections) early.

A number of studies have looked at various vaccines. For example, there is good evidence that the flu vaccine does not cause relapses. When people with MS travel abroad, it is of paramount importance they are adequately protected against possible infections, which may in themselves be life-threatening.

On the other side of the coin, it is well established that pregnancy results in a reduced risk of having a relapse, notably during the third trimester (last three months), when it is reduced by 60 per cent. However, there is an almost identical increase in relapse rate in the three months following the birth. In short, having a baby does not generally alter the course of a woman’s MS, though the practical issues of looking after the baby need to be carefully considered.