Apparently this is all a bit of a mystery.  Those in the know think it’s triggered by a combination of genetic, environmental and, possibly, hormonal factors.This means that some people are born with specific genes that make them more vulnerable to a dodgy immune system.  So everything could be ticking along just fine for years and then a common virus triggers the immune system and stops it working properly.

The female hormone oestrogen can also cause issues, which is why Sjögren’s Syndrome’s symptoms can often rear their ugly head around the start of the menopause, when oestrogen levels begin to fall.  As if women didn’t have enough to deal with at this point.