Mouth breathing

Overview

Mouth breathing is when you breathe through your mouth instead of your nose. It can happen as a habit or because your nose is blocked. Breathing through the nose is better for filtering and warming the air, so mouth breathing can cause problems like dry mouth and poor sleep.

Yes, mouth breathing is common, especially in children and people with nasal congestion from allergies, colds, or sinus problems.

It affects people of all ages but is most common in children, people with allergies or asthma, and those with a deviated septum or other nasal blockages.

Symptoms

Common symptoms

• Dry mouth and throat, especially in the morning
• Bad breath (halitosis)
• Snoring
• Poor sleep quality and feeling tired during the day
• Hoarse voice
• Cracked lips

Symptoms in children

• Poor school performance or trouble concentrating
• Hyperactivity or behaviours that look like ADHD
• Dental problems, such as an overbite or narrow upper jaw
• Dark circles under the eyes
• Frequent ear infections or sinus infections

Symptoms in older adults

• Worsening of snoring or sleep apnoea
• Dry mouth that may cause denture problems
• Increased risk of gum disease and cavities

Causes

Main causes

• Nasal congestion from allergies, colds, flu, or sinus infections
• Enlarged tonsils or adenoids (especially in children)
• A deviated septum (the wall inside the nose is crooked)
• Nasal polyps (non-cancerous growths in the nose)
• Habit – some people continue breathing through their mouth even when their nose is clear

Risk factors

• Allergies, such as hay fever
• Asthma
• Frequent upper respiratory infections
• Exposure to secondhand smoke
• A family history of nasal problems or sleep apnoea

When to see a doctor

See a doctor urgently if:

• If you or your child has difficulty breathing, gasping during sleep, or very loud snoring with pauses in breathing
• If there is a sudden severe inability to breathe through the nose with signs of distress

Book a routine appointment if:

• If mouth breathing lasts more than a few weeks
• If you have chronic dry mouth, bad breath, or snoring that disturbs sleep
• If you suspect you or your child may have sleep apnoea
• If a child is not growing well or has dental changes

Diagnosis

Your doctor will ask about your symptoms, how long you've had them, and any allergies or other health conditions. They will examine your nose, mouth, and throat to look for blockages or swelling.

Tests that may be done

• Nasal endoscopy (a thin tube with a camera to see inside your nose and sinuses)
• Sleep study (to check for sleep apnoea)
• Allergy tests
• X-ray or CT scan of the sinuses (if a structural problem is suspected)

What to expect at your appointment

The exam is usually comfortable. If more tests are needed, your doctor will explain them. You may be referred to an ear, nose, and throat (ENT) specialist for further evaluation.

Treatment

Treatment focuses on fixing the underlying cause. For congestion, self-care and allergy medicine can help. If mouth breathing is due to enlarged tonsils or adenoids, a doctor may suggest surgical removal.

Self-care at home

• Use a saline (salt water) nasal rinse to clear mucus
• Use a humidifier in your bedroom to add moisture to the air
• Sleep on your side or with your head slightly raised
• Avoid known allergens, such as dust mites or pet dander
• Stay well hydrated by drinking enough water
• Practice nasal breathing during the day to retrain your habit

Medical treatments

Doctors may recommend over‑the‑counter or prescription sprays to reduce swelling in the nose (such as nasal steroid sprays), antihistamines for allergies, or decongestant sprays for short‑term relief. Never use decongestant sprays for more than a few days without a doctor's advice. For children, removal of the tonsils and adenoids (adenotonsillectomy) is a common treatment when they are enlarged and causing blockage.

When is surgery considered?

Surgery may be considered if there is a physical blockage that does not improve with other treatments – for example, enlarged tonsils/adenoids, a deviated septum, or nasal polyps. Your doctor will discuss the options and what to expect.

Living with this condition

Managing mouth breathing means treating the root cause and taking care of your mouth and throat. Brush your teeth twice a day, floss, and use a tongue scraper if bad breath is a problem. Drink plenty of water to keep your mouth moist. If you use a humidifier, clean it regularly to prevent mould.

Lifestyle tips

• Quit smoking and avoid secondhand smoke
• Keep allergies under control with medicine or avoiding triggers
• Try nasal strips to help keep your nasal passages open at night
• Establish a regular sleep routine to improve rest
• Consider a chin strap or oral appliance if recommended for sleep apnoea

Diet and exercise

A balanced diet with plenty of fruits and vegetables supports your immune system. Regular exercise can improve your overall breathing capacity. If you have allergies, try to exercise indoors on high‑pollen days.

Mental health and emotional wellbeing

Mouth breathing can affect your sleep, leaving you tired and irritable. It may also cause embarrassment from snoring or bad breath. These feelings are normal. Talk to your doctor – treatment often helps you feel better both physically and emotionally.

Prevention

You can reduce your risk by managing allergies, treating colds early, and avoiding nasal irritants like smoke. For children, early treatment of enlarged tonsils or adenoids can prevent mouth breathing from becoming a habit.

Vaccines

Getting the flu vaccine each year may help prevent the flu and the nasal congestion that can lead to mouth breathing.

Screening programmes

There is no routine screening for mouth breathing. However, if you have risk factors (like a family history of sleep apnoea or structural problems) your doctor may check for it during regular visits.

Complications

If left untreated

• Dental problems – such as overbite, narrow jaw, and increased cavities
• Poor growth in children
• Chronic snoring and sleep apnoea – which can lead to heart problems over time
• Frequent ear and sinus infections
• Changes in facial structure in children (long face, receding chin)

Long-term outlook

With the right treatment, most people can stop mouth breathing or manage the underlying cause. Children often improve after their tonsils or adenoids are treated. The outlook is good – early help leads to better health, sleep, and quality of life.

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