Referred to a consultant rheumatologist

Have been attending my gp for a few weeks now with soreness and stiffness of hands and feet mainly on waking and if I sit down for any length of time. Have lump on my thumb which we had xrayed but found no evidence of arthritis. Had full bloods done but nothing showed up although she says that's quite common. The pain isn't going so she has referred me on as she is convinced it's some sort of arthritic condition (parents both have it ) . Anyone been down this road ? What happens when you see a specialist. What are they looking for ? Is it only arthritis? Also have headaches dizziness palpitations on and off but attributes this to b12 deficiency as it improves greatly after round of injections. Feeling worse week on week and need to get to the bottom of it. Mid 40s and good general health to date. Thanks for reading