Halitosis is a common condition often caused by a build up of bacteria in the mouth because of gum diseases, food or plaque, lack of good dental hygiene etc
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Causes
1)use of alcohol related products
2) certain food
4) lack of good dental hygiene
5)some certain drugs
6)mouth, nose and throat infection
7) diseases etc
How do I know I have halitosis
2) when you notice bad breath from your mouth even after brushing or flossing
2)when people tell you about you having a bad breath
And other ways
Treatment
1) visit a dentist to know what the problem is
2) practice good dental hygiene
3)use of home remedies
4) use of mouth wash
5)use of toothpaste that helps cure odour etc