Halitosis is a common condition in which a person emanates an unpleasant  odour from the mouth, hence it called Bad Breath.
It is estimated that Halitosis affects 1 in 4 people on a regular basis.

Halitosis is the third most common reason that people seek dental care, after tooth decay and gum disease.
There are several  causes of Halitosis but the major is oral hygiene.
Halitosis can cause significant worry, embarrassment, and anxiety  but it is relatively easy to remedy.

Simple home remedies and lifestyle changes, such as improved dental hygiene and quitting smoking, often remove the issue. If bad breath persists, however, it is advisable to visit a doctor to check for underlying causes.

Treatment

The best method to reduce halitosis is good oral hygiene. This ensures that cavities are avoided and reduces the likelihood of gum disease.

It is recommended that individuals visit the dentist for a check-up and cleaning twice a year.

The dentist may recommend a toothpaste that includes an antibacterial agent or an antibacterial mouthwash.

Alternatively, if gum disease is present, professional cleaning may be necessary to clear out the build-up of bacteria in pockets between the gums and teeth.

Causes

Some of the potential causes of bad breath included:
Tobacco: Tobacco products cause their own types of mouth odor. Additionally, they increase the chances of gum disease which can also cause bad breath.

Food: The breakdown of food particles stuck in the teeth can cause odors. Some foods such as onions garlic can also cause bad breath. After they are digested, their breakdown products are carried in the blood to the lungs where they can affect the breath.

Dry Mouth: Saliva naturally cleans the mouth. If the mouth is naturally dry or dry due to a specific disease, such as xerostomia, odors can build up.

Dental Hygiene: Brushing and flossing ensure the removal of small particles of food that can build up and slowly break down, producing odor. A film of bacteria called plaque builds up if brushing is not regular. This plaque can irritate the gums and cause inflammation  between the teeth and gums called periodontitis Dentures that are not cleaned regularly or properly can also harbor bacteria that cause halitosis.

Crash Diets: Fasting and low-carbohydrate eating programs can produce halitosis. This is due to the breakdown of fats producing chemicals called ketones. These ketones have a strong aroma.

Drugs: Certain medications can reduce saliva and, therefore, increase odors. Other drugs can produce odors as they breakdown and release chemicals in the breath. Examples include nitrates used to treat angina, some chemotherapy chemicals, and some tranquilizers, such as phenothiazines. Individuals who take vitamin supplements in large doses can also be prone to bad breath.

Mouth, Nose and Throat Conditions: Sometimes, small, bacteria-covered stones can form on the tonsils at the back of the throat and produce odor. Also, infections or inflammation in the nose, throat, or sinuses can cause halitosis.

Foreign body: Bad breath can be caused if they have a foreign body lodged in their nasal cavity, especially in children.

Diseases: cancers, liver failure, and other metabolic diseases can cause halitosis, due to the specific mixes of chemicals that they produce. Gastroesophageal reflux disease (GERD)can cause bad breath due to the regular reflux of stomach acids.

As earlier mentioned, Halitosis is caused oral hygiene but in rare cases bad breath can be caused by some other medical conditions:

Ketoacidosis: When the insulin levels of a person with diabetes very low, their bodies can no longer use sugar and begin to use fat stores instead. When fat is broken down, ketones are produced and build up. Ketones can be poisonous when found in large numbers and produce a distinctive and unpleasant breath odor. Ketoacidosis is a serious and potentially life-threatening condition.

Bowel obstruction: Breath can smell like feces if there has been a prolonged period of vomiting, especially if a bowel obstruction is present.

Bronchiectasis:This is a long-term condition in which airways become wider than normal, allowing for a build-up of mucus that leads to bad breath.

Aspiration pneumonia: swelling or infection in the lungs or airways due to inhaling vomit, saliva, food, or liquids.

It is worthy to mention that making some lifestyle changes and some home remedies can help in taking care of that offensive odour.

Brush the teeth: Be sure to brush at least twice a day, preferably after each meal.

Floss: Flossing reduces the build-up of food particles and plaque from between the teeth. Brushing only cleans around 60 percent of the surface of the tooth.

Clean dentures: Anything that goes into your mouth, including dentures, a bridge, or a mouth guard, should be cleaned as recommended on a daily basis. Cleaning prevents the bacteria from building up and being transferred back into the mouth. Changing toothbrush every 2 to 3 months is also important for similar reasons.

Brush tongue: Bacteria, food, and dead cells commonly build up on the tongue, especially in smokers or those with a particularly dry mouth. A tongue scraper can sometimes be useful.

Avoid dry mouth: Drink plenty of water. Avoid alcohol and tobacco, both of which dehydrate the mouth. Chewing gum or sucking a sweet, preferably sugar-free, can help stimulate the production of saliva. If the mouth is chronically dry, a doctor may prescribe medication that stimulates the flow of saliva.

Diet: Avoid onions, garlic, and spicy food. Sugary foods are also linked to bad breath. Reduce coffee and alcohol consumption. Eating a breakfast that includes rough foods can help clean the back of the tongue.

If breath odor persists despite controlling these factors, it is recommended that an individual visits a doctor for further tests to rule out other conditions.

Symptoms

The specific odor of breath can vary depending on the cause of the problem. It is best to ask a close friend or relative to gauge your mouth odor, as it can be difficult to assess it yourself.

If no one is available, one way of checking the odor is to lick your wrist, leave it to dry, and then smell it. A bad smell on this area of the wrist is likely to suggest that you have halitosis.

Some individuals are concerned about their breath even though they may have little or no mouth odor. This condition is called halitophobia and can lead to obsessive mouth-cleansing behavior.

All in all, it always good to keep a good oral hygiene.