Is that bad for your hair?
It can be if you do it all the time on a heat setting. However, I sometimes use a blow dryer on a cool air setting if I need to get my hair dried quickly. Heat settings tend to dry your hair out, causing split ends and making it look unhealthy and such. However, it shouldn't hurt your hair much if you use it on a heat setting very infrequently.
Yes, blowing your hair dry is one of the worst things you can do, its not as bad as straightening and bleeching it though.
I blowdry my hair each day and I know lot of people who are doing this. I don't think that my hair is damaged, it's better than having no trims in like 2 years IMO.
I don't think it causes irrepairable problems unless you get it too close to your hair and too hot. The heat causes my hair to frizz big time. But, that may not be a problem for everyone.
Not knowing any better i used to blast my hair with a dryer on high-hot high-speed. I'm paying for that now--the outer inch or two are fried, broken and tangle all the time because the cuticles are broken all over the place. I'm going to have to trim them off eventually.
blow drying also makes hair poof out if it is short enough. if it's long, it will hang down and dry on its own anyway so why not let it. I guess you can use the dryer on low no heat but that seems to be more trouble than just letting it air dry if you ask me.
I blow dry once in a while mostly in the winter cause I don't have time to wait for it to dry and don't want to go out with wet hair.
When I do I use low heat and run my fingers through as I dry so I can feel the level of dryness. I don't blast it till it's crispy I stop when it's still just a tiny bit damp. I haven't suffered badly as a result, although could my hair be better? Maybe but it's ok by me. Also I condition everytime so that helps too.
Kevin
Generally its recommended that if you do blow dry your hair you either use the cool setting (no heat=no damage) or you apply a heat protecting conditioner to your hair before you blow dry with the hot setting. This will massively reduce the damage you can do to your hair by heat styling.
Look for "Thermal Protectors" GHD do a range for use with their styling irons.