Is it Fibromyalgia or simply arthritis? Or..?

I was reading that a woman in her fifties had been a hairdresser for decades. She has a lot of pain in her arms and was diagnosed with Fibromyalgia. Could it be arthritis from holding her arms up all day most days for years? People get carpal tunnel syndrome from using their wrists and forearms on computers a lot and I think CT is arthritis.