I have Polymyalgia Rheumatica (PMR)which started in my hands, exactly as you describe. It is caused by your immune system attacking the connective tissue in your joints. If what you have is PMR, the doctor will prescribe steroid treatment which takes away the pain and swelling very quickly. The sooner you get a diagnosis and treatment, the less severe it becomes. If it is PMR and it is left untreated, it will evolve to affect your neck, shoulders, hips and upper thighs. You should see your doc asap.