system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why does weather changes causes joint pain for those with joint damage or arthritis?

I think the component is barometric pressure changes, but I still don't understand why that should do anything to only joints with some kind of damage, arthritis, or MS. As someone who has slipped a disk and have some mild arthritis or MS I do feel considerably more poorly when some weather changes start rolling in. My back, shoulders, elbows and hands are all sore to the touch and my back  gets stiff. 

Followup question: What can I do to counteract this problem? 

(I saw two other threads on this question, but I didn't see a real answer to either of them Thought it was worth a re-ask.)
gpt
There's no conclusive research on this. The main idea is when barometric pressure drops soft tissue expands. This puts pressure on joints, causing pain. For someone with preexisting joint issues like arthritis this would feel more noticeable. 

There's not much to do other than prevent swelling. I've met patients who have to up their pain meds during inclement weather. For others gentle compression or physical therapy are enough. 

If this pain concerns you talk to your healthcare provider about your options. Best wishes.