Muscular pain long time. Whats cause?

Dear sir i am suffering from muscle pain in legs and hands primarily started from right calf area. After 2 weeks pain became worse..even i was not able to walk with right leg. Then i have gone to neuro phy and MRI of spine done and found disc bulge in lumbar spine may cause pain and used some medicines as per his prescription but no use. Then i consulted an ortho surgeon and MRI of right calf muscle has done and reported s/o polymyositis and s/o edematious changes and he suggested me to consult rheumatologist. followed his suggestion gone to him. He conducted 2 tests CPK and Aldolase enzyme and ANA(anti neuclear anti body) tests.CPK is normal ANA is negative but Serum Aldolase is elevated(ref:1.5-7.5 result:18.2). He presribed corticosteroids(weysolene) using for 40 days. Now i consulted a Sr Gen Phy he conduted 6 tests(CRP ESR ALD ANA RA FACTOR ANTI Jo-1 anti body) and all results found normal including Aldolase. Am confusing first aldolase elevated now normal in 30 days. whats cause?