If you start feeling flu-like symptoms, you may be getting a sinus infection. Visit a medical professional as soon as possible so you can receive antibiotics if you need them. Nasal washes can also help reduce the mucus produced from the nose to the throat.
Halitosis that is caused by a persistent dry mouth is due to a lack of saliva. Because your saliva washes away the leftover food particles that can make your breath smell, an inadequate amount of it can mean those particles stay put. Drinking water is an easy way of mimicking saliva, and will help to rinse away the debris that leads to bad breath. Keep a water bottle with you whenever possible so you can sip on water throughout the day to keep bad breath at bay

While eating any type of food can lead to bad breath, as the bits of food end up becoming a meal for the bacteria that call your mouth home, garlic tends to be the worst offender. In part, that’s because garlic contains sulfur compounds that get absorbed into the bloodstream and that take some time to break down.
It was also marketed to dentists as a way to kill germs in the mouth, but no one paid much attention until the 1920s. That's when, as Inglis-Arkell writes, the owner of the company, Jordan Wheat Lambert, and his son, Gerard, came up with a marketing plan that would forever change the dental aisle. The key was an old Latin phrase that had long dropped out of general usage and which, according to writers over at Cracked, meant “unpleasant breath.” A 1928 ad for Listerine reads in part: “No matter how charming you may be or how fond of you your friends are, you can not expect them to put up with halitosis (unpleasant breath) forever. They may be nice to you—but it is an effort.” Bettmann/CORBIS