Bad breath: causes, symptoms and what to do

What causes bad breath?

Cleveland Clinic says the main cause is poor oral hygiene, which lets bacteria build up. Other causes it lists include dry mouth, gum disease, tonsil stones, nose, throat or lung infections, diabetes, acid reflux, head and neck cancers, kidney or liver disease and smoking. Garlic and onions can cause temporary bad breath. Cleveland Clinic's tartar page adds that tartar usually has an unpleasant odor and can create pockets between teeth and gums where bacteria and food debris collect.

Is morning breath normal?

Yes. Healthline calls morning breath extremely common. Saliva drops during sleep, and saliva normally clears away odor-causing bacteria, so odor builds overnight. Some medications make dry mouth worse. Healthline also lists poor oral hygiene, periodontal disease, strong-smelling foods eaten in the evening, tobacco and acid reflux as causes. Cleveland Clinic's halitosis page does not address morning breath specifically.

How to remove bad breath fast, and keep breath fresh all day

Cleveland Clinic says treatment depends on the cause, and that brushing twice a day, flossing daily and regular dental cleanings help most people. Mouthwashes that kill bacteria work better than those that only mask odor, drinking water and chewing sugar-free gum can help with dry mouth, and avoiding alcohol, caffeine and tobacco also helps. It says mints only cover the smell until the compounds leave your system. Scraping the tongue is especially important, because bacteria and food debris collect there. Healthline suggests brushing before bed, then not eating or drinking afterwards, brushing again on waking, flossing, using an antiseptic mouthwash, cleaning retainers and orthodontic devices daily and drinking plenty of water.

How to avoid stinky breath

Healthline adds avoiding garlic, onions and coffee in the late afternoon and evening, quitting tobacco and chewing sugar-free gum to stimulate saliva. For acid reflux, it says a doctor may prescribe nighttime acid reducers or suggest sleeping more upright. Cleveland Clinic's oral hygiene advice is to brush at least twice a day with fluoride toothpaste, floss daily and brush the tongue with a toothbrush or tongue scraper. See our guides on tongue care and rinsing after brushing.

How do you tell if you have bad breath?

Cleveland Clinic says sniffing your own hand is unreliable, so ask someone you trust, and that a useful rule of thumb is that if you have a bad taste in your mouth you have probably got bad breath that others can smell. If you cannot ask anyone, a dentist can tell you. The sources we read give no advice on how to tell someone else they have bad breath, so be kind and private, and suggest they see a dentist if it persists.

Is bad breath contagious?

The pages we read do not address this. Bad breath is a symptom, not an infection you catch, though bacteria related to gum disease can be shared. Some causes behind it, such as throat or sinus infections, can be contagious in their own right. If it persists, see a dentist.

What are suck-swallow-breath and fast breathing in a sleeping baby?

These are not bad breath topics, and the sources we read do not cover them. If your baby is breathing fast or hard, grunting, pulling in at the ribs or turning blue or pale, seek urgent medical care. For feeding questions, such as the suck, swallow, breathe pattern, ask your pediatrician or a lactation consultant.

When to see a dentist or doctor

Cleveland Clinic says to see a dentist if bad breath persists despite good hygiene, since a dentist can check for oral causes and refer you to a periodontist if gum disease is advanced, and that if the dentist finds no oral problem a primary care provider can check for other conditions such as reflux, diabetes or medication side effects. Healthline says periodontal disease needs dental treatment such as deep cleaning, and GERD-related odor should be addressed with a doctor.

Questions to ask your dentist

Ask for an exam of your gums and tongue.

• Is my breath coming from my gums, teeth, tongue or somewhere else?
• Do I have gum disease or tartar that needs a cleaning?
• Is dry mouth or a medicine contributing?
• Which mouthwash and tongue cleaner suit me?
• Should I see my doctor about reflux or another condition?

Guides in this topic

Frequently asked questions