Swollen hands and feet, severe pain in hands, can't bend fingers

Hi, I'm posting this on behalf of my wife who's life is being turned upside down with the following symptoms which our GP is failing to diagnose....

1. Her hands are swollen constantly and she cannot extend her fingers flat, or make a fist and she is in constant pain but it is a lot worse at night and she wakes up every night around 4-5am in excruciating pain in her hands, she says that along with the pain, her hands feel like the skin in really pulling like the hands are going to explode. She is constantly tired due to lack of sleep.

2. Her feet and ankles are swollen and she can longer wear most of her shoes, but I don't think she suffers any real pain here

3. In the morning, or after a period of inactivity, i.e. sitting in a chair for an hour, she struggles to stand up, her knee joints "click" like they need some lubrication to get her moving, but after a while it eases, although not completely and she stuggles to walk up stairs etc.

4. She has been sweating profusely during the night

5. She has recently had anaemia, although recent blood tests indicate her haemoglobin levels have returned to normal through iron supplements and being fitted with a coil.

6. She has a thyroid condition and has to take daily medication for this.

Our GP has finally referred her to an Arthritis doctor, so we are hoping he finds something, but the NHS system is slow and she is still waiting for an appointment date.

Please, does anybody have these symptoms and has had a diagnosis, or may know what is causing this?

My wife has had these symtoms for about approx 4 months now, which I appreciate is not a large amount of time to live with this pain, but she was previously very fit and healthy, but this has all happened relatively quickly and she and I are obviously concerned there is something wrong and we want to get it fixed as soon as possible so she can get on with her life.

Thanks for taking the time to read this.

Thanks
AP