I have bad breath, and I do not know what to do. No matter how frequent I floss, brush my teeth or use a mouthwash, I find that my breath still smells unpleasant. My colleague told me that the cause of my bad breath could be more serious than I think.. Should I visit the doctor to find out the cause?

1. Gum Disease

Gum disease causes bad breath. One 2012 study found a direct relationship between periodontis and gingivitis to bad breath. This halitosis resulted from the bacteria inhabiting the mouths of the suffering patients.

2. Cancer

Don’t freak out and think because your mouth is unpleasant that you have cancer. But, cancers of the mouth do create many complications for quality of one’s breath. In others, bad breath may actually help reveal an early stage cancer. A director at the Cleveland Clinic’s respiratory center has tested a device designed to recognize lung cancer in 80% of patients – based on a test of the patient’s breath. As bad as it is, a symptom such as chronic bad breath could be a life-saver.

3. Allergies

If you suffer from allergies, bad breath may afflict you in addition to the scratchy throat, stuffy nose and watery eyes. Mucus and nasal drip provide a fertile breeding ground for the nasty germs that cause bad breath. Often when eliminating allergy symptoms, you experience dry mouth. This too causes bad breath. While it may appear a no-win situation, eliminating the nasal drip and keeping your mouth clean and fresh can offer a degree of freedom from both allergies and bad breath.

4. Diabetes

Diabetics suffer from inadequate insulin production. This leads the body to burn fat, a condition known as ketoacidosis. Which in turn leads to an increase in ketones, which the body attempts to eliminate through urine and the lungs. This leads to a breath that has a fruit like odor or odor like acetone. (Acetone is a by-product of ketone production. Ketones are created when the body burns fatty acids).

5. Liver Disease

Patients suffering from liver disease experience a bad breath known by science as fetor hepaticus. This musty smell of breath has been found to indicate liver disorders, often before they manifest through other more obvious means.

6. Kidney Failure

Bad breath has also been found to indicate possible kidney failure. Researchers speculate this may be due to metabolic changes that lead to dry mouth, lack of saliva flow, and an altered sense of taste. All of these contribute to halitosis as the saliva flow fails to cleanse the mouth.

7. Chronic Acid Reflux

Suffering from chronic acid reflux is bad enough. For those that do, keeping the mouth cleaned is imperative. A review of several studies on patients suffering from GERD (Gastroesophogeal Reflux Disease) found halitosis frequently plagues these patients. The influx of acids and other partially digested material into the esophagus and mouth cavity can create problems for keeping the oral cavity clean.


Dr Raymond Lim has been at the forefront of patient-centric dental care services and professional expertise since 2005.

The National University of Singapore (NUS) alumnus who received a Bachelor of Dental Surgery (B.D.S) has advanced, with three years at National Dental Centre treating trauma and emergency patients and a two-year post at polyclinics as the overall in charge. His subsequent years in private practice have further spurred his passion in implantology; He was awarded Certification of Aesthetic Implant Dentistry from the University of Uclan (UK) in 2011.

With determined motivation to provide professional treatments with skill, precision and absolute dedication, he harnessed his years of experience in different sectors of the dental health industry to start his own practice.