Thank you very much for contacting healthcare magic.... According to your complain you have problem of persistant coughing that can lead any lung condition... You are not mention a duration and colour of cough.That one help in diagnosis.... Sputum culture test than start antibiotics course under doctor s suggestion.... Chest X ray can done for further diagnosis... If any lung infection or lesion present than it can deyect in chest x ray... Consult a pulmonologist for further diagnosis... Detail history and investigation helpful for diagnosis give exact idea... I hope my guidance helpful to you.. Take care. Thank you.