Hi. I understand your concerns. Asthma is chronic and a common problem causing symptoms. You will need to undergo pulmonary function test which is needed for diagnosis and also to assess severity of asthma based on which treatemnt can be started. also not night shifts but sugar chemicals and bagasse may cause lung problems. Consult a pulmonologist for the same. if you are from bangalore you can consult me at my clinic at hebbal kempapura. Details are given in practo. Hope your questions were answered. Thanks.