Sleep and Breathing

Normal Breathing During Sleep

Keeping the air passages open during sleep is critical to normal breathing and normal breathing is important to obtaining restful sleep.

In normal breathing, air passes easily through the nose and mouth, inward into your lungs, moving past the structures in the nose, mouth and throat.

Nose and Nasal Airway

The function of the nose is to warm, humidify and filter the air we breathe, preparing it to enter the lungs and bronchi.

The turbinates in the nose are responsible for heating and moistening the passing air. The size of the turbinates fluctuates in response to inhaled irritants, allergens, colds, medicines and cold remedies, etc. If the turbinates swell up too much, they can cause a nasal obstruction.

Other structures, normal and abnormal, in the nose can also cause partial or total airway obstruction, leading to snoring and sleep apnea. Nasal-sounding speech, abnormally decreased sensitivity to odours, and mouth breathing can also be indications of nasal obstruction. These obstructions impair breathing, which can interrupt proper sleep patterns.

Mouth and Throat

The structures of the mouth and throat normally allow an open airway so you can breath easily. During sleep, however, some of these structures relax. For non-snorers, the airway stays open so air can move easily into the lungs. For snorers, the structures relax too much and the airway can become partially or totally blocked. This has a significant negative effect on good sleep.

The following structures are significant to snoring and sleep apnea.

Image of snoring problem


  1. Soft Palate

    The soft palate is a curtain of soft tissue extending from the roof of the mouth into the throat. This tissue blocks the opening between the mouth and the nose during swallowing. In the presence of a partially obstructed airway, the soft palate can vibrate, causing snoring.

  2. Uvula

    The uvula is a floppy, finger-like projection of tissue that hangs down and back from the middle of the soft palate and can also vibrate, causing snoring.

  3. Tonsils and Adenoids

    The tonsils and adenoids are sack-like structures located along the side walls and back of the throat. These tissues are part of the body's immune system. They usually shrink after puberty. They can get quite large if they become infected and they can partially obstruct the airway. Tonsils and adenoids are the primary factors in a child's snoring and sleep apnea.

  4. Tongue

    The tongue is the large muscle at the floor of the mouth that is important for taste, speech, chewing and swallowing. The tongue's significance to snoring and sleep apnea is that it can relax and fall backwards, partially or fully obstructing the airway. The size of the tongue is an important factor in snoring and sleep apnea.