Why Is Morning Breath So Bad?


What is morning breath? Why is it so bad? What causes it? And why the morning? And how come nobody ever has “afternoon breath” (well, that guy in the mail room is an exception — he always reeks!) Let’s answer those questions here today.

To start, “morning breath” is really just plain old bad breath, called halitosis. As I’ve discussed in a previous blog, halitosis is a common problem that has a variety of causes (from diet to lifestyle to oral health issues to chronic medical conditions in certain people [1] ). But while not everyone has an issue with chronic halitosis, almost ALL of us have some type of morning breath. That’s what makes it so interesting. 

I can hear you now: “Okay Dr. Connelly, morning breath is just plain old halitosis. But why the morning?” 

Well, to answer that question, we have to first go to one of the common causes of halitosis — dry mouth. When your mouth is dry, bacteria have a field day. See, your saliva washes away and control bacteria, so when it’s not there, bacteria thrive. And what do those bacteria do when left to themselves? Well, imagine schoolchildren without the teacher or principal — they’ll have a field day, causing all kinds of mischief. They munch on compounds, proteins, amino acids and leftover foodstuffs in your mouth and teeth, and produce volatile sulfur compounds (VSCs) which, well, stink [2]. To get a bit more specific for you chemistry people, the VSCs responsible are believed to be hydrogen sulfide (H2S), methyl mercaptan and dimethyl sulfide. These VSCs are generally produced through the bacterial metabolism of sulfur amino acids like cysteine and methionine. [3]

Okay, chemistry class is over — the bottom line is, bacteria crunch and much away in a dry mouth, and the result is bad breath. So that brings us back to the morning. You see, as we sleep, saliva production is markedly reduced [4]. This allows those previously mentioned bacteria to thrive and do their thing, resulting in — ta-DA — morning breath. 

Yes, it really is that simple — morning breath generally comes from drymouth, which causes bad breath. 

Now, there are a few other enhancers to morning breath. Take the groovy bar people we met in the opening of this post. They probably drank some alcohol (which further dries out the mouth), perhaps had a cigarette or two, and then stopped at the diner, where bar guy had home fries with onions. Then, when they tumbled back to his apartment, brushing their teeth was the last thing on their minds. The result is the little scene played out above (sorry, we won’t get into other scenes, as this is a family blog!). Although, I personally don’t advocate mouthwash (which probably contains alcohol). But brush those teeth, kids. 

Now to the question I get asked often as an Beverly Hills Cosmetic Dentist — just HOW can I prevent morning breath?

Well, to start, there’s really no outright, foolproof prevention. Your body doesn’t produce saliva when you sleep, and you need to sleep, so the breeding ground will always be there. That said, there are a few things you can do the lessen morning breath:

Brush and floss right before you go to sleep. This will clean out your mouth and get rid of any food particles. This gives those pesky bacteria less “food” to munch on. This lessens the byproducts (the VSCs we discussed). 

Hydrate before going to sleep — drink some water. No, it’s not saliva, but it’ll help a little.

If you get up during the night, again, drink some water. It can’t hurt. 

Limit alcohol intake. Yes, it’s pretty obvious, and Groovy Couple would disagree with me (and they have a minor point — the alcohol may have contributed to the entire scene happening in the first place). Still, maybe the “drink, water, drink, water” combination I mentioned in another blog might be prudent. The goal is to try and keep your mouth from totally drying out.

Don’t smoke. I know most people don’t nowadays, but it’s still worth mentioning.

And for goodness sakes, no onions on the 2 a.m. home fries! 

I realize a lot of these are pretty obvious and somewhat frivolous, but they will all help with that dreaded morning breath.

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Beverly Hills Dentist