Morning breath is the term that people use to describe breath that smells bad when a person wakes up. Dry mouth and poor oral hygiene are common causes of morning breath.

The Academy of General Dentistry have estimated that 80 million people in the United States experience chronic bad breath. However, there are many straightforward ways to treat morning breath.

Keep reading to learn more about what causes bad breath in the morning and what to do about it.

a woman yawning and looking slightly uncomfortable because she has morning breathShare on Pinterest
Good oral hygiene can help prevent morning breath.

Morning breath is a type of bad breath that affects people when they wake up. The medical term for bad breath is halitosis, which describes chronic bad breath that does not go away.

According to the American Dental Association (ADA), morning breath occurs due to a buildup of bacteria in the mouth overnight.

Food particles

During the night, the enzymes in saliva will break down food particles remaining in between teeth, on the tongue, or around the gumline. This breakdown releases volatile sulfur compounds (VSCs), which give off a bad smell.

The specific foods that a person eats can also influence how their breath smells. The list of foods that can cause bad breath is very long and includes:


Smoking can also cause bad breath. A person may not be aware of the effect that smoking can have on their breath odor because smoking dampens the sense of smell.

Dry mouth

A person may experience morning breath if they have a dry mouth. Saliva helps the mouth clear out bacteria that build up over the day and night. If the mouth is not producing enough saliva, bacteria will be able to build up more often. As a result, the release of VSCs overnight may be higher, potentially causing morning breath.

One study that investigated the effect of water on morning breath found that drinking water or rinsing the mouth with water in the morning reduced VSCs by 30–50%, leading to an overall improvement in morning breath.

Breathing through the mouth can also dry it out. People who sleep with their mouth open or snore heavily may have a drier mouth and be more likely to have bad breath in the morning.

Poor oral hygiene

Poor oral hygiene is a common cause of morning breath. Proper brushing and flossing remove bacteria and food particles that cause bad breath.

If a person does not regularly and effectively clean their teeth, they could also develop tooth cavities and gum disease. Gingivitis and periodontitis are types of gum disease that can cause bad breath.

Tooth cavities resulting from bacteria that produce plaque can trap more bacteria in the mouth, as can the deep pockets that gum disease causes. A person can then find it hard to clean the bacteria away when they brush their teeth.

The cause of morning breath can be as simple as poor dental hygiene, especially if it leads to complications. Tooth decay or a “dead tooth” can cause bad breath that may be even worse in the morning.

However, certain underlying chronic conditions that are not directly related to the mouth can sometimes be responsible for an unpleasant breath odor.

For instance, untreated diabetes can be a cause of bad breath. Some infections — such as tonsillitis, sinusitis, and bronchitis — and fungal infections of the mouth, lips, and tongue can also have an adverse effect on the breath.

In some cases, liver or kidney disease may result in bad breath.

A person will experience other symptoms alongside bad breath if an underlying condition is the cause.

People can often improve their morning breath by doing the following:

Keeping the mouth clean

A person can treat morning breath or longer lasting halitosis by improving their dental hygiene.

Brushing the teeth twice a day and cleaning in between them with dental floss or interdental brushes can keep mouth bacteria under control. A person can also use mouthwash to help clear bacteria out of the mouth.

One study on the effectiveness of mouthwash against morning breath found that the daily use of mouthwash significantly reduced the number of bacteria in the saliva. Flossing and mouthwash can also ensure that no food remains in the mouth overnight.

A person can also use a tongue scraper as part of their brushing routine to remove bacteria from the tongue. Tongue scraping is a gentle technique, but some people may find it uncomfortable because it can trigger the gag reflex.

Anyone who wears removable dentures should take them out at night and clean them thoroughly before wearing them again the next day.

It is also important to make regular visits to the dentist to help maintain oral hygiene.

Drinking more water

A person may find that increasing their water intake and reducing how much caffeine and alcohol they consume leads to an improvement in their breath odor.

Staying well-hydrated by drinking water can increase the amount of saliva that the mouth produces, which will help keep mouth bacteria under control.

Caffeine, alcohol, and smoking can dry out the mouth. Certain types of medication can also have this effect.

Learn more about how to maintain good mouth hygiene here.

Usually, there is no need to worry about waking up with morning breath.

However, if a person finds that their morning breath is not going away with conventional treatments, such as improving dental hygiene and keeping their mouth from becoming dry, they may need to seek advice from a dentist.

A person should see a dentist if:

  • they have a constant bad taste or smell in their mouth
  • they are experiencing other new symptoms along with bad breath
  • they spit blood when they brush their teeth

Blood in the saliva after brushing the teeth can be a sign of gum disease and requires medical treatment. If the dentist finds that the odor is not due to oral factors, they may advise the person to consult a doctor.

A person may experience poor mental health and self-esteem if they are aware that they have morning breath or halitosis. They may feel constantly stressed about having bad breath, which might adversely affect their social life and relationships.

If a person is very worried about morning breath or halitosis, a psychiatrist may be able to help them overcome their anxiety around this issue.

Morning breath is very common among the general population, and it does not usually last long into the day.

A person can improve their breath odor by brushing the teeth thoroughly, using mouthwash and dental floss, and staying hydrated to stop their mouth from becoming dry.

A person should seek medical advice if their bad breath does not go away or if they are experiencing symptoms of an underlying condition that may also be causing bad breath.