Bad breath - also known as halitosis - is a chronic condition that can be caused by several factors. Having stinky breath after eating a garlic-rich meal or in the morning is common and natural. Persistent bad breath, however, may be the result of factors such as:

- Poor dental hygiene: Food particles can get stuck in between the teeth and will begin to be broken down by bacteria in the mouth. This process can produce a foul smell. The bacterial plaque that forms on teeth as a result of poor oral hygiene can lead to tooth decay and gum disease, so it is especially important that you regularly brush and floss your teeth.

- Dry mouth: Saliva helps clean your mouth by washing away particles and debris. Because of this, decreased saliva production can lead to bad breath. Decreased saliva production frequently occurs during sleep or as a result of smoking or xerostomia - the medical term for chronic dry mouth. In addition, some medications can cause dry mouth, leading to bad breath.

- GERD: Gastroesophageal reflux disease - or chronic acid reflux - causes stomach acid or fluids in the stomach to work their way back into the esophagus, which can result in bad breath.

- Infections: Gum disease (such as gingivitis) or other infections in the mouth, nose, or throat can cause bad breath.

- Cancer: Oral cancers and oropharyngeal cancer (cancer of the cavity at the back of the mouth) can cause bad breath.

Bad breath can be embarrassing. In some cases, bad breath may signify the presence of a serious medical condition such as an oral infection, or cancer. If improving your oral hygiene doesn’t help the condition, seek medical attention. Many cases of bad breath can be treated with improved hygiene and dental care, but if the condition is being caused by a medical problem or medication usage, further treatment may be needed.