Wheezing while laying down commonly occurs with asthma, allergies, anxiety, chronic obstructive pulmonary disease (COPD), gastroesophageal reflux disease (GERD), or sleep apnea. Wheezing when lying down can also be caused by mucous draining from the sinuses due to a cold, flu, allergies, or sinus infection. If you experience wheezing when lying down and are not diagnosed with any of the above, see your healthcare provider to determine the cause.