One of the defining characteristics of RA is morning stiffness and joint pain, so that's certainly a vote in that column. On the other hand, with fibromyalgia, the pain and stiffness increases after prolonged periods of inactivity, which can also explain the pain and stiffness - you mentioned that if you stay still for too long, you get stiff and have more pain, so that sounds like fibro. I have both RA and fibro and have discovered that one of the ways to keep fibro pain at bay is to fidget a lot. When I'm awake, I make sure I move around every 30 min. or so, because the more still you are, the more your body seizes up. The fact that your Cymbalta prescription seems to have improved things also speaks to you having fibromyalgia, as antidepressants can be very helpful for this condition.

You mentioned you don't have any swelling and that is also one of the defining characteristics of RA. However, there are many forms of arthritis, so just because you don't have any swelling doesn't mean you don't have a type of arthritis. You describing your joints are feeling hot and tight also speaks to arthritis and the symptoms in your ankles are definitely worrisome. Of course, it's also possible that you have both the time of arthritis and fibromyalgia, but it's hard for me to say which. What is less hard for me to comment on, though, is your nurse practitioner's statement about how we all get ache as we grow older. You don't mention how old you are, but in my opinion, a medical professional dismissing your symptoms as belonging to the natural progression of age right after they admit yours is a confusing case to me seems to indicate that they're more comfortable shrugging off your symptoms rather than admitting they don't know what's going on and sending you to someone who might.

I'd recommend that you go back to your rheumatologist - not the NP - to talk more details about what's going on. Before you do that, do some research and our basics of RA area, as well as the fibromyalgia area of our Chronic Pain site so you know more about the different diseases which will help you formulate better questions. Also check out my post on how to be a good self advocate, because that's what you're going to have to do. Talk to your doctor in more detail about what's going on, about certain of your symptoms improving, but others not, ask questions about other types of arthritis, ask them about whether this could be RA despite not having any swelling, etc. Have you had any x-rays? If not, ask for some to see if there's any erosion in your joints - although it usually takes quite a while for joint damage to occur, this is almost one of those situations where you sort of wish that you had just the teensiest bit of joint damage, because it would indicate that you have something akin to RA. In other words, I'd suggest you push harder.

Good luck! Please keep us posted on what happens?