It is THE BURSA That surrounds the OLECRANON PROCESS. Yes RA must influence that as well.

Both of my elbows filled with fluid, and it's called bursitis. I had to have them operated on by an Orthopedic doctor. The sacs were the size of golf balls,

The liquid is synovial fluid. The sac is the bursa

If you have heating pad because it’s so cold out and can take ibuprofen that will help. Hopefully it is not infected if it is you will have to get antibiotics for it and that’s when you see the doctor. Ice for all Ortho problems is for the first couple of days but it’s too cold for me. Bursitis most times goes away on its own. Sometimes steroid injections help when needed. But I get just a tinge of bursitis not much and I put Volteran Gel on it.

Both of my elbows filled with fluid, and I had to have an Orthopedic doctor remove them. My right elbow had a couple of nodes in it. Please see a doctor.