Sjögren’s Syndrome is a systemic auto-immune disease characterised by dry mouth and dry eyes and various auto-immune changes, confirmed by a blood test or salivary gland biopsy.
Sjögren’s syndrome can occur as an independent, primary condition, “Primary Sjögren’s syndrome”, or accompany another auto-immune disease, such as rheumatoid arthritis, in which case it is known as Secondary Sjögren’s syndrome.
In addition to dryness of the mucous membranes and skin, Sjögren’s syndrome can also lead to:
general symptoms such as fatigue, musculo-skeletal pain and less commonly
pathological changes in internal organs and
various complications such as caries (dental decay), candidosis (Thrush), congenital heart block and lymphoma.
Sjögren’s syndrome can have profound effects on the mouth (hence its inclusion on this web-site).
This is a broad subject and other people / websites explain it far better than me.
I list here some very useful websites and also a variety of articles about Sjögren’s Syndrome.