<unk>  is caused by a complex interaction of environmental and genetic factors that researchers do not yet fully understand. These factors can also influence how severe a person’s<unk>  is and how well they respond to medication. As with other complex diseases, many environmental and genetic factors have been suggested as causes of<unk> , but not all studies posing such claims have been verified by further studies. In addition, as researchers detangle the complex causes of<unk> , it is becoming more evident that certain environmental and genetic factors may affect<unk>  only when combined.
Asthma causes
Bronchiolitis causes
Bronchiectasis causes
Bronchitis causes
Occupational lung disease causes
Tracheitis causes
Occupational lung disease risk factors
Bronchiolitis risk factors