What can cause arms and legs worsening pain and stiffness for weeks? bilateral swollen axillary lymph nodes for months without infection.

Get checked. : Arm & leg pain & stiffness for weeks (you're talking about the joints, & no sports or overuse injuries, right?) suggests arthritis or an autoimmune issue: that needs a checkup to sort out. Persistent nontender axillary nodes are also problematic. We could talk all day about "possibilities"; but you need an in-person evaluation in order to get the help you need. Hope that helps.