The optimal way to breathe in general is through the nose, says Nancy Collop, MD, president of the American Academy of Sleep Medicine
. Our noses warm the air and filter out dirt and other particles. Breathing through the mouth, especially while sleeping, can lead to snoring, throat irritation, intense dry mouth and even abnormal respiration and sleep apnea. Another problem, says Collop, is that mouth breathing while lying on your back can cause the tongue to fall back and partially obstruct the upper airway. Nasal strips can help you get in the habit of breathing comfortably through your nose. If they don't, you may want to see an ear, nose and throat specialist.