Why Does It Smell When I Floss?

Bad breath has gone from something that people just lived with to an embarrassing but very common social stigma.

Why Does It Smell When I Floss

It’s currently estimated that 1 in 4 people live with bad breath and experience it regularly. 

Whilst the easiest way to tell if you currently have bad breath is to simply smell your own breath, or even ask a loved one or friend to check it, there are also a number of other ways to check. 

One of the key indicators of the condition of your breath is your floss string. 

If you’ve completed your oral hygiene routine, but you notice that the floss smells bad, then the likely cause is bad breath. 

In this article, we’ll be discussing why it might smell when you floss, including the likely cause of the foul odour and some ways to prevent it. 

So if you’re someone who experiences a bad smell when you floss, or are just curious about bad breath in general, read on!

Why Does It Smell When I Floss? 

As mentioned in our introduction, the most common cause of floss smelling bad is bad breath. 

Also known as halitosis, bad breath can be extremely off-putting, and can also make the sufferer very self-conscious. 

The main reason why floss smells bad after use is because of rotten food particles, usually meat or fibrous foods, becoming stuck between the teeth. 

After roughly 24 hours, if the food particles aren’t removed, they start to decompose. The nasty smell on the floss is actually sulfur gases released by this decomposition. 

Below we’ll outline some other main causes of bad breath. 

Other Causes Of Bad Breath

Why Does It Smell When I Floss (1)

Whilst food particles decomposing in the gaps between your teeth is the main cause of bad breath, there are also a number of other causes. These include but are not limited to: 


If you’re a smoker, you’ll definitely have noticed that smoking leaves an unpleasant odor after a cigarette. 

Smokers and those who use chewing tobacco are at a much higher risk of developing gum disease. Gum disease is another main cause of bad breath.

Gum Disease 

Cavity-causing bacteria known as plaque not only damages your teeth but can also irritate your gums. 

When plaque isn’t regularly removed from the teeth, it can build up below the gum line and trap odour-causing bacteria. 

Dry Mouth 

Whilst dry mouth can occur naturally during sleep or if you sleep with your mouth open, some people can suffer from persistent dry mouth. 

Certain medications can cause dry mouth. This can cause bad breath because your saliva plays a vital role in oral health because it regulates the amount of bad breath causing bacteria. 

Certain Medications 

As mentioned above, certain medications can cause bad breath. So it’s worth checking the information of any medications you take.

When the body breaks down certain medications, they release gases which smell similar to sulfur.

Medical Conditions

There are a number of medical conditions that can cause bad breath, despite regular brushing and flossing. 

These include things like diabetes, certain cancers, gastric reflux, or liver/kidney disease. 

Is There Any Way To Treat Bad Breath? 

If you’re on top of your oral hygiene routine but still suffer from bad breath, it’s worth considering a trip to your doctor. 

As mentioned above, certain medical conditions can lead to bad breath, so it’s always worth getting a check-up. 

Gum, specialised toothpaste, and mouthwashes are readily available and specifically designed to combat bad breath. 

If you could do with establishing a better oral hygiene routine, then definitely do this first, as it’s the backbone of your arsenal for getting rid of bad breath. 

Another way to combat bad breath is to make sure you are hydrated. 

This might seem like stating the obvious, but hydration is essential in maintaining oral hygiene, amongst a host of other benefits. 

Ensuring that you are drinking water regularly will help get rid of unwanted bacteria in your mouth. 

The Takeaway 

The main message is that if your floss smells bad, this is a strong indication that there is a build-up of harmful bacteria in your mouth. 

If you notice that the floss smells bad after use in multiple places in the mouth, you could have halitosis. 

The reverse is also true, if the floss only smells when used in one area, the problem might be contained to that part of your mouth. 

The best ways to combat bad breath are: 

  • Brush twice a day for a maximum of 2 minutes 
  • Use toothpaste with fluoride 
  • Flossing at least once a day 

If the problem persists then you might want to consider seeking the advice of a dental professional. 

Persistent bad breath coupled with a bad smell when flossing can be a sign of gum disease or even tooth decay. 

Andrew Kemp
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