Smell of bonfire

Over the last three years when I have had a bad cold or virus; my sense of smell has reduced to virtually nothing. But when in bed (so horizontal) I have experienced from time to time a feint smell of burning bonfire! Losing your sense of smell is bad enough but now I am concerned there is an underlying medical reason for it. I can see others are experiencing this from the site but I do remember many years ago reading that it could be an indicator of something serious. Any ideas?!

[LivingInHope]

Loss of smell caused by a cold is supposed to clear up on its own.  If you have loss of sense of smell other times, you should get brain tumor ruled out.  Losing one's sense of smell can happen naturally to some extent with aging and I heard if it is to a certain degree, it could be an indication that someone may develop Alzheimer's disease.  Found more info on this subject.  See private message.