Chronic cough and anaemic .

Patient: My mother is an Indian woman (age 48) . She is having a chronic cough for more than 1 year, though treated but relapses repeatedly afte medication is stopped. Different test like PFT, chest xray has revealed nothing suspicious. She is anaemic also .Her weight is 52 kgs and height is 5′ 1″. How to cure this cough? Is there any problem inside her like cancer or something else

Symptoms: Coughing sometimes lead to vomiting, sometimes looks very weak,