The registered peak flow of 500 does not indicate that you are losing or have lost your lung function. It may just be a reflection of sub-optimally controlled asthma. The so-called “predicted” or “normal” peak flows are average peak flows for a person of a specific gender, height and age, nothing more. Every person has a Personal Best peak flow; that is the best flow you (Bogboy82free) will ever have when your lungs are completely clear. It remains to be seen what your personal best peak flow will be, when your asthma is optimally controlled.
Peak flows are fine for monitoring asthma control but are not pulmonary function tests of a type that spirometry is.
You may, therefore, need medical attention to achieve optimum control of your asthma. When that point is reached, spirometry will answer the question of whether lung function has been lost, or not. Your peak flow at that time will be your personal best.
Good luck
I forgot to mention the brand i purchased as bad ratings due to low scores Omron PF9940 PeakAir Peak Flow Meter.
I forgot to mention i smoked marijuana for over 10 years and quit recently im scared i have COPD.
I just tested again and it's 420-450, i guess the 500 was a fluke. im worried sick now.