My  father who is 78 years old and experiencing breathing difficulties. I am sharing his medical reports with you for your review. Here are the symptoms we have observed: After lunch, he usually takes an afternoon nap. When he wakes up, he has trouble breathing, along with a wheezing sound. This typically happens after his afternoon sleep. He feels better after using his inhaler. Then during rest of evening this problem is not seen. Even after waking up in the morning, there is no breathing problem. We also observed that when he takes a nap *before* lunch, he does not experience this breathing problem or wheezing. What is he suffering from?