Hello my name is Matthew. Exactly 8 days ago, my right inner knee began bothering me with pain, stiffness, and swelling. Now it is much worse especially when I first wake up out of bed. Ironically, my right shoulder is painful for about an hour mainly when I attempt to raise it. I did fall about 7 weeks ago but I had no problems until now which may not even be related. If you could just give me your opinion or some advice that I may ask my doctor, I would appreciate it. I'm worried that this may be an autoimmune arthritis disorder because of how it progressed and, I was diagnosed with Guillen Barre Syndrome in 2011 which you obviously know is an immune disorder. Thank You, Matt.
Go and see an experienced Orthopaedic surgeon
It is possible that it has a rheumatological cause. It's better to see a rheumatologist first.
If no injury, then likely inflammation. Motrin and ice may help. A steroid injection would be next. An exam may be needed to see if MRI is needed for cartilage problem. Shoulder could be rotator cuff related.