There are many possible causes. 

Food. The breakdown of food particles in and around your teeth can increase bacteria and cause a foul odor. Eating certain foods, such as onions, garlic and spices, also can cause bad breath. After you digest these foods, they enter your bloodstream, are carried to your lungs and affect your breath. 

Tobacco products. Smoking causes its own unpleasant mouth odor. Smokers and oral tobacco users are also more likely to have gum disease, another source of bad breath. 

Poor dental hygiene. If you don’t brush and floss daily, food particles remain in your mouth, causing bad breath. A colorless, sticky film of bacteria (plaque) forms on your teeth. If not brushed away, plaque can irritate your gums and eventually form plaque-filled pockets between your teeth and gums (periodontitis). Your tongue also can trap bacteria that produce odors. Dentures that aren’t cleaned regularly or don’t fit properly can harbor odor-causing bacteria and food particles. 

Dry mouth. Saliva helps cleanse your mouth, removing particles that cause bad odors. A condition called dry mouth or xerostomia (zeer–o-STOE-me-uh) can contribute to bad breath because production of saliva is decreased. Dry mouth naturally occurs during sleep, leading to “morning breath,” and it worsens if you sleep with your mouth open. Chronic dry mouth can be caused by a problem with your salivary glands and some diseases. 

Medications. Some medications can indirectly produce bad breath by contributing to dry mouth. Others can be broken down in the body to release chemicals that can be carried on your breath. 

Infections in your mouth. Bad breath can be caused by surgical wounds after oral surgery, such as tooth removal, or as a result of tooth decay, gum disease or mouth sores. 

Other mouth, nose and throat conditions. Bad breath can occasionally stem from small stones that form in the tonsils and are covered with bacteria that produce odor. Infections or chronic inflammation in the nose, sinuses or throat, which can contribute to postnasal drip, also can cause bad breath. 

Other causes. Diseases, such as some cancers, and conditions such as metabolic disorders, can cause a distinctive breath odor as a result of chemicals they produce. Chronic reflux of stomach acids (gastroesophageal reflux disease, or GERD) can be associated with bad breath. Bad breath in young children can be caused by a foreign body, such as a piece of food, lodged in a nostril. 

There are some quick and easy ways to banish bad breath. Just remember, the odor from what you eat can stick around until the food works its way completely out of your system — up to 3 days later! 

Bad breath can be reduced or prevented if you: 

Practice good oral hygiene. Brush twice a day with fluoride toothpaste to remove food debris and plaque. Brush teeth after you eat (keep a toothbrush at work or school to brush after lunch). Don’t forget to brush the tongue too, or use a tongue scraper. Bacteria on your tongue can contribute to bad breath. If you can’t brush after a meal, give your mouth a good rinse with water to at least loosen up and free those trapped bits. Replace your toothbrush every 2 to 3 months or after an illness. Use floss or an interdental cleaner to remove food particles and plaque between teeth once a day. Rinse with an antibacterial mouthwash twice a day. Antiseptic mouthwash can help kill bacteria that cause bad breath and plaque that can lead to gingivitis, an early, mild form of gum disease. Adding a fluoride rinse to your daily routine can help prevent tooth decay. Dentures should be removed at night and cleaned thoroughly before being placed in your mouth the next morning. Clean braces and retainers as directed by your dentist. 

See your dentist regularly — at least twice a year. They will do an oral exam and professional teeth cleaning and will be able to find and treat periodontal disease, dry mouth, or other problems that may be the cause of bad breath. 

Stop smoking and chewing tobacco-based products. Ask your dentist for tips on kicking the habit. 

Drink lots of water. This will keep your mouth moist. Chewing sugarless gum or sucking on sugarless candy also stimulates the production of saliva, which helps wash away food particles and bacteria. Gums and mints containing xylitol are best. 

Eat more fruits and vegetables and less meat. Apples, carrots, celery, and other hard fruits and vegetables help clear odor-causing plaque and food particles from your mouth. 

Keep a log of the foods you eat. If you think they may be causing bad breath, bring the log to your dentist to review. Similarly, make a list of the medications you take. Some drugs may play a role in creating mouth odors. 

Who Treats Bad Breath? 

In most cases, your dentist can treat the cause of bad breath. 

If your dentist determines that your mouth is healthy and the odor is not of oral origin, you may be referred to your family doctor or to a specialist to determine the odor source and treatment plan. You can go over a list of your medications with them to see if any of them could be contributing to the problem. Work with them to keep diabetes, allergies, and other conditions under control. 

If the odor is due to gum disease, for example, your dentist can either treat the disease

Your treatment will vary depending on the cause of your bad breath. For example, if your halitosis is caused by plaque buildup or periodontal disease, we may begin treating you with a deep cleaning. we may also recommend a change in your oral health habits to ensure your bad breath does not return. 

If your halitosis is caused by decayed teeth or by the presence of not good restorations  so you will need our help to treat this problems