If your child is a habitual mouth breather, he may need help. If left untreated, regularly breathing through the mouth instead of the nose can have serious health repercussions for children. According to Dr. Yosh Jefferson in the April 23, 2010 edition of "U.S. News and World Report," mouth breathing in children is far more serious than most people assume. Jefferson says that people who breathe through the mouth are "literally dying a slow death that robs them of their appearance, health, longevity and quality of life."

Symptoms

If your child is a mouth breather, she will breathe primarily with her mouth open and her breathing will often sound shallow and raspy. She may snore, have dark circles under the eyes, seem sleepy or inattentive and have chronic bad breath. Mouth breathers tend to grow at a slower rate than other children, have a smaller chin and jaw, have dry lips and swollen tonsils, according to the website of dentist Dr. Joseph Sarkissian.

Causes

Allergies are the primary cause of mouth breathing. Children with chronic or severe congestion may find it difficult to breathe through the nose, and may get in the habit of breathing through the mouth, reports Medical News Today.

Other causes of mouth breathing include a deviated, or crooked, septum, long-term use of a pacifier and enlarged tonsils. Additionally, if your child sucks her thumb, her lower jaw may become recessed, resulting in a constricted airway and a greater probability she will resort to breathing through her mouth, notes Dr. Sarkissian.

Appearance

Mouth breathing can lead to bone abnormalities that alter the shape of your child's face, causing changes in the appearance that may prove difficult to correct. If your child is a mouth breather, she may have crooked teeth and a gummy smile. Her face may appear overly long and narrow, and her jaw may visibly protrude.

Growth and Development

If your child breathes through her mouth, it may affect her growth and development. Mouth breathing robs the body of oxygen and causes many children to sleep poorly. If your child sleeps poorly, her body may not release the growth hormones needed for proper development, and she may appear smaller than average for her age, reports Medical News Today.

Children who breathe through the mouth may encounter difficulties in school. Lack of sleep can lead to poor concentration and difficulty completing tasks, and mouth breathers may be diagnosed with attention deficit disorder or labeled as hyperactive. If your child has problems concentrating in school, check with your doctor about possible health-related issues.

Health Effects

Dr. Steven Y. Park, an ear, nose and throat specialist in New York, says that mouth breathing can negatively affect your child's heart rate and blood pressure. Mouth breathing can also dampen your child's sense of taste and smell, which may lead to suppressed appetite or weight problems. Also, mouth breathing may cause the tonsils to swell and become visibly enlarged. Over-sized tonsils can obstruct your child's airway, making it even more difficult for her to breathe through the nose.

Treatment

If your child's mouth breathing is due to allergies, his condition may improve with medication. Talk to your child's doctor about the efficacy and possible side-effects of treating mouth breathing with allergy medication.

Your doctor may recommend surgery to treat mouth breathing. An ear, nose and throat surgeon may choose to remove swollen tonsils and adenoids to help your child breathe through the nose. Dentists can fit your child with appliances designed to widen the palate and open the sinuses and nasal passages.

Warning

If your child consistently breathes through his mouth, take him to a doctor or a dentist for evaluation. Mouth breathing can have serious, lifelong effects and most children will require some form of treatment.