Is Persistent Dry Cough With Nasal Blockage And Thin Mucus A Major Issue?

My mother age is 56 yrs she is having dry cough for last ten days earlier coughing was more in night compare to daytime and nasal were blocked and now coughing is same as night and nasal are blocked, thin mucus is coming with coughing. I gave her ascoril LS dry cough syrup and gargle , steam , Ginger tea but she feels that due to overheat its not getting fine. Please suggest and confirm its not major issue