I seem to cough a lot and have trouble clearing my throat. When I do clear my throat (not much mucus) I stop coughing. I am 68 and do get shortness of breath when moving up and down the beach in the sand or walking long distance. My oxygen levels always seem to be good, 90. I do smoke and that probably causes most of my issues. My mother died of IPF (idiopathic pulmonary fibrosis) rather quick after being aware she had it. I do find it strange that I will go into coughing spell a lot after eating.