Hello dear, Thank you for your contact to health care magic. I read and understand your concern. I am Dr Arun Tank answering your concern. Dry cough has wide etiology. I suspect that your mother is having a common viral infection. As the season right now is not good. For dry cough codiene phosphate should be taken. This will suppress the cough, but it should be taken only under your doctors guidance because it will not be given to you without doctors prescription letter. Please do advice your mother regular gargle by hexidine. It will clear your Throat infection. Respiratory exercise can be help full. I advice deep breathing in and out. Regularly whenever you remember to do it. Infection can be spread to other family members so that it can be prevented to other by good practice. I will be happy to answer your further concern on bit.ly/DrArun. Thank you, Dr Arun Tank Infectious diseases specialist, HCM.