Bad breath, also known as halitosis, can be caused by a variety of conditions. Certain health issues can lead to bad breath, as well as other negative side effects. Frequent respiratory infections and systemic organ illnesses are conditions that can cause chronic bad breath.
For some people, recurrent or severe respiratory problems can lead to bad breath. Infections or illnesses that affect the nasal passages, such as pneumonia and chronic sinus infections or sinusitis, can cause a bad smell. This is generally a result of postnasal drip, which occurs when excessive mucus is produced during an immune response and accumulates in your throat or nose. The mucosal buildup harbors odor-causing bacteria and food particles in the back of your mouth and throat, causing an unpleasant smell. In conditions like bacterial pneumonia, the lungs fill with liquid in a process known as consolidation. This leads to severe bad breath from the lungs and mouth as a result of high levels of bacteria and fluid.
Bad breath may also be caused by liver or kidney issues. Late-stage liver failure can lead to a unique form of bad breath, also known as “fetor hepaticus,” which is caused by dimethyl sulfide. Alternatively, chronic kidney failure is also associated with bad breath that smells fishy or ammonia-like. This form of bad breath is called “uremic fetor”; the smell is caused by an elevated urea concentration in saliva and its subsequent breakdown into ammonia.
Other symptoms often accompany these medical issues that cause bad breath. These may include congestion, sinus pain, chest pressure, or an elevated body temperature. The obvious solution to curing bad breath that is caused by an underlying medical issue is to treat the individual cause. This can involve antibiotics for a sinus infection or more extensive procedures for organ issues. Improving oral hygiene through regularly flossing, brushing, and mouthwash usage is also important to limit the extent of medically caused bad breath and to prevent additional oral-health concerns.