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Halitosis, or a persistent bad breath, is more than embarrassing. It affects personal and social life, causing a loss of self-esteem and confidence. Halitosis, however, is quite common in healthy people and is something that mouthwash or chewing mints can barely solve, which is unlike “morning breath” and may be a sign of something more serious.




Prevalence and awareness


A large study performed in Japan involving 2,672 individuals indicated that 6-23% of the subjects had bad breath. As there is no specific study among our population, the prevalence of bad breath in Hong Kong is unknown but still with significant concerns.




What Causes Halitosis?


Halitosis may encompass both oral and non-oral causes.


Poor dental hygiene:


Our mouth is home to hundreds of bacterial species. Cavities give bacteria places to hide in the mouth that are difficult to clean out by brushing teeth or mouth washing. Volatile sulphur compounds (VSCs) in producing bacteria was recently understood as the main cause of halitosis. Other compounds causing oral malodour including hydrogen sulphide (H2S) and methyl mercaptan (CH3SH) are known to be associated with bad breath.


Smoking and dry mouth:


Saliva keeps the mouth moist and at a healthy ph balance. The inhalation of smoke, however, can slow down saliva production and aggravate the condition of dry mouth. Dehydration is another major cause of bad breath.


Nasal polyps and sinusitis:


Some polyps in the nasal passages can probably affect the sense of smell, the ability to breathe through the nose. Polyps may develop with chronic sinusitis. Patients with nasal polyps tend to suffer from sneezing with a persistent post-nasal drip. The symptoms include nasal obstruction, yellowish or greenish nasal discharge, and bad smell from the nose. Citizens with the family history of nasal polyps and sinusitis are at higher risk. Exposure to leather tanning as well as wood dust may increase the risk of developing nasal polyps and sinusitis. Cases of eye complications arising from sinusitis are also presented.


Chronic tonsillitis and tonsilloliths:


Tonsils are the immune system's first line of defence against ingested or inhaled foreign pathogens. They are collections of lymphoid tissue facing into the aerodigestive tract. Chronic tonsillitis is caused by repeated attacks of acute tonsillitis in a longer period. Sometimes the symptoms milder than the acute phase including sore throat, pus within the tonsillar crypts, a muffled voice, painful swallowing, difficulty breathing in the night, enlarged lymph nodes in the neck, fever, and the foul-smelling tonsil stones. The infection, however, can lead to halitosis.


Tonsilloliths are aggregates of bacterial and cellular debris that form in the tonsillar crypts where form the small calcium deposits – called tonsil stones. The yellow curds look like cottage cheese on the tonsils. They may cause the inflammation of painful tonsils and can produce white pus. Patients with tonsil stones usually suffer from bad breath.




Patients with sialadenitis may find the foul-smelling pus that drains into the mouth and lumps in the cheek or under the chin. Sialadenitis is the inflammation and swelling of major or minor salivary glands, commonly obstruction or ascending infection or both.

Sjögren’s syndrome is another common salivary gland disorder and preferentially attacks females older than 40. The symptoms of Sjögren’s syndrome include dry mouth, dry eyes, sores in the mouth, dry cough, and swollen salivary glands. Sialadenitis may also be associated with fever, ear pain, pus draining through the gland into the mouth, and a salivary gland swelling. Patients with systemic diseases, such as diabetes, may also suffer from sialadenitis.


Oral Cancer:


Although we cannot presume that bad breath will definitely relate with cancer, we should be highly aware that it could be a potential if uncommon. Oral cancer symptoms usually occur around the mouth, teeth and glands. If patients suffer from constant bad breath, any persistent and painful oral ulcer showing no sign of healing lasting for one month with a "volcano-like" appearance, raised edges and hard surfaces, bloodstained saliva and cervical lymph node enlargement should find out whether it is due to cancer or some other causes, i.e., Leukoplakia and erythroplakia. Leukoplakia generally refers to a firmly attached white patch on a mucous membrane and cannot be rubbed off. It has a twisted shape with raised edges that often appear inside the mouth and under the tongue. The risk of malignancy is from 0.6% to 20%. When the white patch is turning red, or red lesions appear, it indicates an increased risk of cancer with 90% of irregular growth or severe malignancy .


Nasal and Sinus Cancer:


It affects the nasal cavity and the sinuses. Patients suffer from a persistent blocked nose, nosebleeds, a decreased sense of smell, mucus running from the nose, and mucus draining into the back of the nose and throat. Infections or chronic inflammation in the nose, or sinuses can lead to bad breath. Chronic postnasal drip and sinus drainage are also bad-breath causes.


Other chronic conditions:


While, halitosis is often linked to an underlying health problem. For instance, it could be a sign of gastric reflux, diabetes, liver or kidney disease.


Regardless, there is no shame in having halitosis. If you have a similar experience, you may receive advice from our ENT doctors.



How is Halitosis diagnosed?


Diagnosis of dental problem:


Dentists often diagnose halitosis. The diagnosis is based on the patient's history and mouth odour during the regular check-ups.


Diagnosis of nose, mouth and throat infections:


  1. Nasopharyngoscopy: A nasopharyngoscopy will be advised when patients are suffering from the symptoms in the nose or throat including recurrent nosebleeds, nasal polyps, chronic sinusitis, and suspected nasal cancer.
  2. CT scans: A check-up for paranasal sinuses can help determine the sinusitis. For patients with suspected sialadenitis, doctors may recommend a CT neck scan to check the neck abscess or small stones.
  3. USG salivary glands: Ultrasound is useful for the diagnosis of different disorders of salivary glands. In acute inflammation, salivary glands are enlarged and hypoechoic with increased blood flow. If positive, it shows the existence of a tissue that is more dense than usual.
  4. Microlaryngoscopy: Patients who are suffering from vocal problems (i.e. hoarseness, cysts, polyps) may seek for doctor’s advice if a microlaryngoscopy is needed.


Handling Halitosis


Once the exact cause is pinpointed, the halitosis can be treated in several ways.


Oral hygiene:


If patients notice that the breath has been less than fresh lately, they are highly suggested to brush with a fluoride toothpaste and apply the alcohol-free mouthwash to create more of a balance in the mouth.


Quit smoking:


Smoking is also a major cause of bad breath. While quitting can reduce the risk of halitosis in a significant way, but does not bring it to zero.


Nasal polyps and sinusitis:


Patients may relieve the symptoms by taking oral medications and using nasal spray. If symptoms aren't improving or are getting worse, patients will be advised to have functional endoscopic sinus surgery, or maxillectomy to solve the nasal problem.


Chronic tonsillitis and tonsilloliths:


Treatment for tonsillitis should depend on the cause. Doctors will give treatment with antibiotics to cure the acute infection. Antibiotics may be given as a single shot or taken a few days. Recurrent tonsillitis, however, is another case. It may be diagnosed if an individual has multiple bouts of tonsillitis in a year. Ultimately, the ENT doctor may recommend having the tonsils removed (or Tonsillectomy) if it is diagnosed as recurrent or chronic tonsillitis.




Management of sialadenitis involves the medical way and the surgical approach. Medical management includes hydration, using antibiotics and analgesic, and giving gland massage. Surgical methods including sialendoscopy with stone removal or gland excision can also be applied.




Surgery, chemotherapy, radiation therapy work well in treating oral cancer and nasal and sinus cancer.




*The above information is for reference only, please consult your doctor for detail.