My mother has a cough from 4th July after she had some thing cold. She has no blocked nose fever or head ache ( had top of the head pain first 2-3 days when coughing) .  We visited a nearby GP on 10th and she said both throat and chest look clear (not done xray) and this looks like an upper respiratory tract infection. The cough has come down and she is able to sleep at night but in the day she still coughs once ever hour and the cough sounds congestion filled thick. How long will this take to heal and should she go back to the doctor to get antibiotics ? Is a CT scan needed or will Xray do.