Sjögren's is usually described as an immune attack on the glands that make tears and saliva. That description is accurate and it is not the whole picture.
The glands sit in the head and neck, in a dense region of fascia, lymphatic vessels, and nerves. The same territory carries the vagus nerve, the drainage pathways for the face and skull, and the muscles that tighten when a body has been in pain or on alert for a long time.
The model I work from is a loop. Inflammation in that region causes the surrounding fascia to tighten and guard. Tight fascia compresses the lymphatic vessels that were supposed to clear the inflammation out. The inflammation stays. The nervous system, reading persistent irritation, stays in a defensive state. A nervous system stuck in defense reduces glandular secretion and amplifies pain signaling.
Each part of that loop makes the next part worse.
Which is why treating only the immune component, or only the dryness, so often leaves people still exhausted, still aching, and still not recognizably themselves.
I want to be honest that this is a framework, not established consensus in rheumatology. It is how I make sense of what my patients describe and what I feel under my hands, and it is consistent with a growing literature on fascia, lymphatic function, and pain sensitization. I am telling you how I think so you can judge it for yourself.