Health information to help you understand symptoms. It isn't a diagnosis.
Check symptoms

Bad breath

Also called: Halitosis

Bad breath is very common and usually comes from bacteria on the tongue and between the teeth. Brushing, flossing, cleaning your tongue, and drinking water usually help. Gum disease, dry mouth, sinus or tonsil problems, and some foods can also cause it. Bad breath that doesn't improve with good oral care should be checked by a dentist.

Common causesMouth bacteria, gum disease, dry mouth, foods, smoking
Usually serious?Usually not
Get checked ifIt doesn't improve with good oral care
If you think it's an emergency, call 911.Thinking about suicide? Call or text 988.

Overview

Most bad breath starts in the mouth when bacteria break down food bits and release smelly gases. Morning breath is normal because saliva slows during sleep.

Garlic, onions, coffee, alcohol, and smoking can cause bad breath. Gum disease, cavities, dry mouth, tonsil stones, sinus infections, and postnasal drip are other causes. Rarely, a fruity, fishy, or ammonia smell can signal diabetes, kidney, or liver problems.

When to get medical care

Call 911Not an emergency.
Get care todayBad breath with fever, severe sore throat, or facial swelling.
See a doctor soonBad breath that doesn't improve after 2 weeks of good oral care. Bleeding gums, loose teeth, or tooth pain. White lumps in the tonsils. Dry mouth that lasts. Fruity breath with thirst and peeing a lot.

Causes

Common causes include poor oral hygiene, bacteria on the tongue, gum disease, cavities, dry mouth, foods, smoking, and alcohol. Other causes include tonsil stones, sinus infections, postnasal drip, acid reflux, dentures, and, rarely, diabetes, kidney failure, or liver disease.

OwieClear has pages on 2 conditions that can cause bad breath. Each shows how soon to get care.

Common causes

  • Bad breath (halitosis)Often treated at home

    An unpleasant mouth odor, usually from bacteria on the tongue and between the teeth.

  • Tonsil stonesOften treated at home

    Small, white or yellow bits that collect in the pockets of the tonsils.

What you can do at home

  • Brush twice a day and floss daily.
  • Clean your tongue with a brush or scraper.
  • Drink water and chew sugar-free gum.
  • Clean dentures daily.
  • Don't smoke.
  • See a dentist every 6 months.

Medicines

Your dentist may treat gum disease or cavities and recommend an antibacterial mouth rinse. Other causes are treated based on what's found.

At the doctor

The dentist will look for mouth causes first.

Questions you may be asked

  • When it's worst
  • Oral care habits
  • Dry mouth
  • Sinus or throat symptoms
  • Smoking and diet

The exam

A dental and mouth exam.

Tests

  • Usually no tests

Prevention

Good oral care helps.

  • Brush, floss, and clean your tongue
  • Drink water
  • Don't smoke
  • Regular dental visits

Check your symptoms

Most symptoms have more than one possible cause. The symptom checker looks at all of your symptoms together, plus your age, and shows how soon to get care.

Start the symptom checker

Sources

Last updated 2026-11-13.