I would like to know how these peak flow level work for people. What level is the normal high and whether your levels drop down severely when you suffer from chronic asthma attack. I also want to know how long it takes for you to return to your normal level again after an attack. I find that my levels are always at the same level and do not vary much even though it is nowhere near my good and normal levels. I want to know what time will the Prednisone and other medicines take to get my levels high again. I would be extremely grateful if someone could shed some light on this matter and clear my doubts for me as soon as possible.