If you think that all bad breath comes from the mouth, you couldn't be further from the truth.
There are several things that can cause bad breath that have nothing to do with the mouth at all. For example, many people that have a problem with kidney disease often have a problem with halitosis. Not because it is causing a problem with the mouth, but the disease often discharges toxins through the blood and they are then expelled through the lungs. The same is also true of liver problems and diabetes, both of which can cause bad breath.
You might be surprised to learn, however, that the real cause of your bad breath might be right under your nose. This is the case when it comes to a sinus problem as the infection that causes sinus problems can often cause a foul odor as well. Many people are surprised when they learn that the halitosis that they have been dealing with and trying to remove actually has nothing to do with her mouth at all. If the odor is actually coming out of your nostrils, no amount of treatment that you do inside of your mouth and no breath mint is going to be able to cover over the problem.
Typically, sinus problems are something that come and go and for this reason, the bad breath may come and go as well. There are some times, however, whenever you may be dealing with sinusitis that is chronic. This either happens as a result of allergies that we may be dealing with regularly or perhaps even birth defects that block the sinus cavities in some way or another. If this is the case with you, he may be next to impossible for you to get rid of the odor that is detected as halitosis, at least without getting rid of the sinus problems that you are dealing with.
Two things that you can do in order to treat this kind of a sinus problem is nasal rinsing, often using a neti pot.
Many people find this type of treatment to be unsavory but once you get used to the sensation, it is actually quite pleasant. You might also want to talk to your doctor about the possibility of opening up your sinus cavities a little bit in order to allow proper drainage to take place. If you're able to successfully get rid of the sinusitis, you can successfully get rid of the bad breath that goes along with it.