Hello,
Have u fiqured out what is your red zone is ? That is your critical zone, that means you should seek professional help.
This is the reason u do them so your doctor can monitor these reading, i have kept medical records, peak flow meter reading, (diet, exercise, triggers and what u did that day, weather too)for over 15 years.. i have been very ill since a doctors error. Your peak flow reading is telling you that there is a trigger around you that is bothering your lungs.. Is your bedroom enviorment totally sterile, very little as the way of furnishings and change your filters on your furnace. It could be the cold.. keep track of everything and this way when your doctors ask you what you did that day, a diary can be extremely helpful, and over time u may be able to discern what is triggering you so that your peak flows drop, the more information on bad days the better.. Good luck old timer peak flower!