What is causing your bad breath?

Most bad breath starts in the mouth, mainly from bacteria on the back of the tongue. Some comes from the nose, throat, diet or medical conditions. Each guide covers one cause, how to recognise it, and what actually fixes it.

• How do you get rid of garlic breath?To get rid of garlic breath, eat raw apple, raw lettuce or fresh mint leaves, or drink milk, during or right after the meal, then brush your teeth and clean...
• Can bad breath come from your stomach or gut?Bad breath from the stomach is possible, but it is the exception: reviews estimate that about 90% of bad breath starts in the mouth, mostly from bacteria on...
• Can acid reflux cause bad breath?Yes, acid reflux can cause bad breath. When stomach contents rise into the throat or mouth, you can get a sour, acidic smell and taste, and studies link...
• Is bad breath after a tooth extraction normal?Mild bad breath for the first few days after teeth removal is common, because blood, healing tissue and trapped food sit in the socket while you clean less...
• Why does post nasal drip cause bad breath?Post nasal drip causes bad breath because extra mucus runs down the back of your throat and settles on the back of your tongue, where odor-producing...
• Why do I have bad breath during pregnancy?Bad breath during pregnancy usually comes from changes pregnancy brings to your mouth and body: hormones make gums more prone to inflammation (pregnancy...
• Why does dry mouth cause bad breath?Dry mouth causes bad breath because saliva is your mouth's natural rinse: it washes away food and bacteria and keeps odor-producing bacteria in check. When...
• Can a sinus infection cause bad breath?Yes. The NHS lists bad breath as a symptom of sinusitis, alongside facial pain, a blocked nose and thick yellow or green mucus. The smell comes from...
• Can gum disease cause bad breath?Yes. Persistent bad breath is a recognized symptom of gum disease, listed by NIDCR and the NHS alongside bleeding, swollen gums. Bacteria living in plaque...
• Can tooth decay cause bad breath?Yes. MedlinePlus lists cavities and abscessed teeth among causes of bad breath. Holes in teeth, cracked fillings and decay under old crowns trap food and...
• Can wisdom teeth cause bad breath?Yes. Wisdom teeth that are partly through the gum, crowded or hard to reach can trap food and bacteria, and a flap of gum over a half-erupted tooth can...
• Why does fasting cause bad breath?Fasting causes bad breath mainly because you are not eating or chewing, so saliva flow drops and coating builds up on the tongue, where bacteria produce...
• Can dehydration cause bad breath?Yes. When you are dehydrated your body makes less saliva, and a dry, sticky mouth lets odor-producing bacteria build up on your tongue. That is why breath...
• Does vaping cause bad breath?Vaping appears to raise the chance of bad breath, though the evidence is newer and weaker than for smoking. A large 2025 survey found people who only vaped...
• Does mouth breathing cause bad breath?Yes. Breathing through your mouth dries it out, and without saliva rinsing your tongue and teeth, odor-producing bacteria build up. Cleveland Clinic lists...
• Which medications cause bad breath?Medications cause bad breath mainly by reducing saliva: NIDCR says hundreds of medicines can cause dry mouth, including some for high blood pressure,...
• Why do braces cause bad breath?Braces do not cause bad breath by themselves, but brackets and wires trap food and plaque in places that are hard to clean, and that plaque can lead to...
• Why does coffee give you bad breath?Coffee causes bad breath in two ways: its strong aroma compounds cling to your mouth, and caffeine can dry your mouth, letting odor-producing bacteria build...
• Can allergies cause bad breath?Yes, allergies can cause bad breath, mostly indirectly. Allergic rhinitis (hay fever) can cause post nasal drip, a blocked nose that makes you breathe...
• Why do my dentures cause bad breath?Bad breath from dentures usually comes from three things: plaque and food building up on the denture itself, wearing dentures overnight, and not cleaning...
• Why does smoking cause bad breath?Smoking causes bad breath in several ways at once: smoke leaves odorous residue in the mouth and lungs, it reduces saliva, it shifts the bacteria in your...
• Why do you get bad breath after drinking alcohol?Bad breath after drinking alcohol comes from two things: alcohol dries your mouth and dehydrates you, which lets odor-producing bacteria build up on your...
• Are tonsil stones causing your bad breath?Tonsil stones can cause bad breath, and Cleveland Clinic calls it their most common symptom. They are small lumps of hardened debris and bacteria lodged in...
• Can diabetes cause bad breath?Yes. Diabetes raises the risk of gum disease, dry mouth and thrush, and all three can cause bad breath; NIDDK lists bad breath that does not go away with...
• Why does my toddler have bad breath?Most toddler bad breath comes from ordinary causes: bacteria on the tongue and teeth, breathing through the mouth while sleeping, or early tooth decay. A...