There are three (3) usual sources of bad breath: sinus, dental, and stomach problems. It seems like everyone has nasal and sinus allergies and it's common for patients to have temporary colds that can aggravate them. It's important to keep nasal and sinus fluids moving or they will begin to stink. There really are only nasal problems since almost all sinus problems result from the sinus drain hole into the nose being blocked. When the exit out of the sinus is blocked fluids build up in the sinus and bacteria can grow in them. An important key is to keep the nose moist so fluids can move. Use sea salt spray. It can be squirted into the nose throughout the day. A small bottle of sea salt spray can be purchased at your drug store and you can refill it with normal saline. The pharmacist can get you a large bottle cheaply. Patients with nasal and sinus problems often complain of a metallic taste in their mouth.
The second source of bad breath is dental problems. When you have periodontal problems your gums bleed and the blood sits and rots causing your breath to smell and sometimes causing a bad taste in your mouth. Because your gums swell, pockets around the teeth trap food. The food is very difficult to remove since the pockets are often deeper than 4 or 5 millimeters and brushing isn't effective in removing the food. Food can combine with bacteria to form a sort of yogurt than sticks to your teeth, tongue, and cheeks. Brushing and flossing helps but you have to also brush your gums, tongue, and cheeks. Old dentures can also absorb foods that rot and smell so that removing your dentures at night and soaking them in a cleaner can help.
The third source of bad breath is stomach problems. People often eat foods that don't agree with them and the food cause their stomachs to churn and give off odors that float up through the mouth and nose. The first thing to try is drinking lots and lots of water throughout the day. This keeps the contents of the stomach moving. Then find out which foods disagree with you and stop eating them when you're around people. Keeping a food diary will assist you in remembering what you ate and when you had bad breath.
Those of you that have older relatives in nursing homes may notice that they often have bad breath. This is due to a normal decease in saliva production as we get older and causes a dry mouth and bad breath. Dental professionals call the condition xerostomia. It can be helped by providing ice chips to these patients or using artificial saliva to moisten their mouths.
A helpful prescription product is Periomed. Periomed is a flouride rinse that kills the bacteria that can cause bad breath and periodontal disease. It can also decrease hot and cold sensitivity and the cavities that often accompany a dry mouth.
Of course, you should always seek professional care whenever you are concerned about having bad breath. If it's due to periodontal disease, you will need dental care since brushing will usually not be enough. Remember that bad breath is a sign that something else is wrong.