Source MS Trust: The causes of MS are not well understood and there are a number of factors to be considered. You may wonder whether you did something to cause your MS or if you could have 
stopped MS from happening to you. The answer is ‘no’. No one could have advised you how to prevent your MS.
The cause of MS is a very active area of research and it seems likely that a number of different factors come together to trigger MS. Some of these factors are in the world around us and there is some evidence that lack of sunshine may play a part. Other possibilities include being exposed to certain common viruses and carrying certain genes. However, no one knows for certain. Read on.