What are the causes and symptoms of bad breath?

  • Poor hygiene - This is the most common cause of bad breath. When food particles are stuck between your teeth or elsewhere in your mouth, they get broken down by bacteria that grow there. That process releases a foul smell. The bacteria can also cause tooth decay and gum disease. Brushing your teeth and tongue and flossing help to remove the food residue and control the bacteria.
  • Dry mouth - Saliva helps to wash your mouth, so if your body isn’t making enough saliva, your breath can smell bad. Smoking can cause dry mouth and also increases the possibility of gum disease. Certain medications can cause your mouth to be dry.
  • Cancer in your mouth, or between your nose and your mouth - Other symptoms of oral or oropharyngeal cancer (the oropharynx is between your nose and mouth) include sores that don’t heal, mouth pain, difficulty swallowing, a lump in your neck and unexplained weight loss.
  • Gastroesophageal reflux disease (GERD) - This is a digestive disorder in which stomach acid or fluids leak back into the esophagus, the tube that takes food from your mouth to your stomach.
  • Tonsil stones - When food gets stuck in your tonsils, which are at the back of your mouth on both sides, it sometimes hardens into calcium deposits called tonsil stones or tonsilloliths.
  • Gum disease - Gingivitis is an inflammation of the gums that can cause them to be red, swollen and bleed easily. It is caused by plaque, a sticky film that builds on your teeth and can be removed by brushing and flossing. Trench mouth is an advanced form of gingivitis that can involve intense pain, bleeding, fever and fatigue. (It’s called “trench mouth” because it was a common illness for soldiers in the trenches during World War I.) Untreated gingivitis can lead to periodontitis, which damages gum tissue and can lead to tooth and bone loss around the teeth.
  • Infections in the nose, throat or lungs - Patients with pneumonia, for example, cough up liquid that smells bad.
  • Diabetes - People with diabetes have an increased risk of gum disease, and gum disease can make it harder to control diabetes because it can increase blood sugar.
  • Liver disease or kidney disease - These can lead to bad breath because of the smell of toxic substances that would be filtered out of your body by properly functioning kidneys or liver.
  • Sjögren’s syndrome - This is an autoimmune disease that can lead to dry mouth, dry eyes and dry skin, as well as muscle pain.

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