Bad breath, or halitosis, is very common, and in most people it starts in the mouth, from bacteria on the tongue, between the teeth or around the gums. Good daily care and a dental check fix most cases. When bad breath persists despite that, a GP can look for other causes, such as tonsil stones, sinus problems, reflux, a dry mouth from medicines, or a medical condition. A GP telephone consultation with The Online GP is £59.
Reviewed by the medical team at The Wellness. Last updated 14 November 2026.
Key points
Most bad breath comes from bacteria on the tongue and around the teeth and gums.
Daily brushing, cleaning between teeth and cleaning the tongue help most people.
See a dentist first, as gum disease is a common cause.
A GP can look for tonsil, sinus, stomach and medicine related causes.
A GP telephone consultation is £59, and a video consultation is £150.
What causes bad breath?
The mouth. Bacteria on the back of the tongue, between the teeth and around the gums are the most common cause. Gum disease makes this worse.
A dry mouth. Saliva keeps the mouth clean, so breathing through your mouth, dehydration and medicines that dry the mouth can all lead to bad breath.
Food, drink and smoking. Garlic, onions, coffee, alcohol and tobacco all play a part.
Tonsils. Small, foul smelling stones can form in the tonsils.
Sinuses and nose. Sinus infections and mucus running down the back of the throat.
The stomach. Reflux can contribute in some people.
Medical conditions. Rarely, diabetes, kidney or liver problems cause a particular smell on the breath.
What can I do at home?
Brush twice a day with a fluoride toothpaste
Clean between your teeth every day with floss or interdental brushes
Clean your tongue gently, especially at the back
Drink water regularly and chew sugar free gum to keep saliva flowing
Cut down on smoking, alcohol and strong smelling foods
See a dentist and hygienist for a check and clean
When should I see a GP?
If your dentist has found no cause and the bad breath continues, a GP can help. Your doctor will ask about your symptoms, your medicines and your general health, look at your mouth and throat, and consider causes outside the mouth. That may mean treating reflux or a sinus problem, changing a medicine that dries the mouth, or arranging blood tests for diabetes or kidney and liver function.
See a doctor promptly if bad breath comes with a mouth ulcer that has lasted more than three weeks, difficulty swallowing, a lump in the neck, unexplained weight loss or a persistent hoarse voice.
How can The Online GP help?
Our doctors can assess you by telephone or video, prescribe treatment where it is appropriate, arrange blood tests and refer you to an ear, nose and throat specialist if needed. A telephone consultation is £59, a video consultation is £150, and a same day urgent appointment is £220.
How do I arrange an appointment?
Send us a message on WhatsApp with a few words about what you would like help with, and we will offer you the earliest time with one of our doctors. Appointments run from 7am to 9pm every day by video, and in person at our clinics in Marylebone and Belgravia. You do not need a referral, and you do not need to be registered with an NHS GP.
After your appointment you receive a written summary of what was discussed. Our team then arranges any tests, prescriptions or referrals your doctor recommends, and keeps you updated at each step, so nothing is left for you to chase.
Frequently asked questions
Can a GP treat bad breath?
A GP can look for causes outside the mouth, such as reflux, sinus problems, tonsil stones or medicines, and treat them.
Should I see a dentist or a GP first?
Usually a dentist first, because most bad breath starts in the mouth.
Do mouthwashes help?
They can help for a short time, but cleaning the tongue and between the teeth does more.
Can stress cause bad breath?
Stress can dry the mouth, which can make bad breath worse.
How much is a GP appointment?
A telephone consultation is £59, a video consultation is £150 and a same day urgent appointment is £220.
The Online GP is part of The Wellness, a doctor-led private healthcare group with clinics at 10 Portman Square, Marylebone, and 9 Eccleston Street, Belgravia. All doctors are GMC-registered. Prescriptions are issued only after a consultation and clinical assessment, when the doctor judges them appropriate. In an emergency call 999. This article is general information and not a substitute for medical advice about your own health.
Message us on WhatsApp on +44 7961 280835 (ref OGP-bad-breath-halitosis-private-gp) and we will arrange your appointment.
Sources
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