when I was younger and healthier, I couldnt really tell it. I may have coughed a little more and been a little short of breathe. Now that I have more advanced CF, if I miss a treatment it's a big deal...my chest can hurt, I will have hard coughing, feeling like I cant breathe/get my breath and light activity (like walking) will cause me to become SOB. I do albuterol neb and vest every 4-6 hrs while awake (or if it wakes me up at night from coughing/SOB). I do DNase in the morning and before bed. I have always done 3-4 treatments (albuterol/chest therapy) a day since a young age.