Halitosis, more commonly known as bad breath, affects roughly 25% of the world’s population and is the third most common reason people visit the dentist after tooth decay and gum disease. 
The three main causes of bad breath
The three most common causes of bad breath are:
1. Dental factors
Dental factors include gum disease and poor oral hygiene.
Gum disease (periodontitis)
Gum disease has two stages: gingivitis and periodontitis. Gingivitis is curable and occurs when dental plaque builds on the tooth where it joins the gum.
Periodontitis is advanced (or chronic) gum disease and can occur if gingivitis isn’t treated. Periodontitis affects the part of the gum which seals to the tooth, causing the seal to weaken and spaces form between the tooth and the gum. Bacteria become trapped in these spaces, referred to as periodontal pockets, causing inflammation.
Periodontitis is the leading cause of adult tooth loss in the world. By maintaining a proper oral hygiene routine at home, and regular dental check-ups and cleans you can minimise the risk of gum disease.
Poor oral hygiene
When food particles become stuck in your teeth it can cause odours. This is one of the reasons why it’s so important for you to brush and floss your teeth every day. You should brush your teeth twice a day, chew sugar-free gum after lunch, and drink plenty of water to rinse out your mouth.
Good oral hygiene also includes what you eat. It’s recommended that you consume less sugary food and drink and have more fruit and vegetables. Milk, cheese and yoghurt are also good for your teeth as is not snacking continuously through the day.
Snacking through the day increases the amount of available sugar in the mouth, making it easier for bacteria to destroy tooth structure which leads to tooth decay.
Visit your dentist every six months for a check-up and clean, because a dentist will clean your teeth in a way that brush and flossing can’t. They can also assess your oral health and help you to prevent any serious issues from occurring.
2. Dry mouth/smoking
Saliva cleans the mouth—it’s one of the reasons some dentists recommend chewing sugar-free gum. If your mouth is naturally dry (say, in the morning) or is dry because of a disease then odours can build up.
Smoking also causes the mouth to be dehydrated, robbing your teeth of much-needed saliva.
Diseases such as cancer, liver failure and other metabolic diseases can cause bad breath because of a specific mix of chemicals they produce.
What else causes bad breath?
There are many factors which can cause bad breath, such as gases coming up from your stomach, bacteria that can cause ‘rotten egg’ gas and certain types of medication.
A visit to the dentist can help to find the reason for your bad breath and if the cause is dental, provide you with a solution.