One of my best friends endured years and years of asthma and finally went to National Jewish Health in Denver. They explored all of his ailments for a week. One of the things that they discovered was that he has sleep apnea. They gave him great advice and things to follow and he has never felt better, he feels cured in a away. The Drs in LA had been giving him bad information for a long time. Really recommends the National Jewish Health.