I was a mild asthmatic until a couple of years back and I am wondering if it is the new style inhalors not suiting me? Could it be? I am now on 4 times the preventor dose (which make me cough dispite using spacers)and using releivers regularly and my PF is still lowish compared with 3 years ago. Ofcourse it could be age!! Or the respiratory failure from pneumonia a year back. ( My PF has improved from 150/200 to 250/300 since quadrupling the preventor but was over 400 3 years back).