Well in a way the same way as ciggerates would hurt you IMO. But i think cigs harm u more than weed becase. A cigs dont have any good effect and u fuck up your lungs, and weed has a good effect and probally is better for u cause i like to smoke weed when i have problems with nausea and shit so it helps alot more.. the only bad part is just the tar that the plant material that u inhale to ur lungs.. but there are ways aorund that eating etc.. so seriously i think weed is not bad for you at all.. just about anything is bad for us, like drving a car could kill us faster than the many many years it may take to get cancer or sum shit from smoking weed from all the tar, so i say we should all just light up lol. anyways i guess yes it is bad for u and no its not bad for u at the same time.