First off, I am 99% sure this has nothing to do with her teeth. I have very good oral hygiene myself - 31 years old, no cavities ever, recent dentist visit graded my gums at 0 (4 being awful and 0 being best) so I know how to clean teeth and clean both children's teeth 2-3 times a day without fail. I am also an avid tongue cleaner. And her tongue isn't even coated at all. But all of a sudden, her breath smells really off, and it has never smelt before. It's not horrendous or strong, or even the typical, nasty, rotten, shit-like smell (sorry) you associate with someone who has poor oral hygiene, problems with their teeth/gums or tonsil stones - it's more heavy, gassy, musty, stale, a bit sour - kind of like a burp but with something else I can't put my finger on, though I know I've smelt it before. I'd describe it as an 'ill' smell, but I'm not sure why. It just *is*. Bit of background - she had an awful cold and cough just before Christmas, which resolved after a week or so but she is still coughing occasionally in the day and throughout the night. This breath issue has been going on about a week or so now, but it's only in the last two or three days she has started sniffing/sneezing a lot and seems a little congested though her nose isn't running like it does when she has a cold. She is also burping loads and has the most horrendously smelly gas coming out the other end since yesterday. I'm sure it's all related, I'm just not sure what it is. I wondered about a sinus infection following the cold/cough, which I understand can cause bad breath, but I'm not sure. There's also a chance this could be coming from her stomach, and I feel that is more likely given the nature of the smell and the other gastrointestinal symptoms, but she doesn't seem poorly at all really. Just off. It is also worst in the morning and seems to improve somewhat throughout the day, especially after eating. Wtf? She doesn't appear to have a dry mouth and I am pretty sure she hasn't put anything up her nose. I probably need to take her to the doctor, don't I? At least, if this doesn't improve soon. I seriously hope to god it's temporary. Does anyone have experience with this? Or with sinus infections, stomach problems or even asthma in their kids, and if so, what kind of smells did these produce? I know this is a bit of a gross post, but we're all adults here so I'd love to hear from anyone with any insight. No worries about being graphic or tmi - just want to get this sorted out for my poor kid asap.