i've been smoking like nearly 8 years now, and i hardly ever get sick, 2times a year at most, including common colds (which is usually what i'm sick from) so i think it's just you... if anything, i'd say weed has greatly boosted my immune system.... not to mention, i stay away from as much man-made medicine as possible... i'd rather tough out the sickness, and build my immune system, then be a pansy, get a cough and take medicine....