Hello ! Since when is this problem occuring ?Is it dry cough or there is phlegm ? Is there any increase in cough on exposure to cold, dust or smoke, stress or exercise? Any increase in winter season ? Are there any other complaints apart from cough ? If your answer to the queries pertaining to aggravating factors is an yes then likely diagnosis is cough variant asthma ..
Next Steps
Kindly elaborate on the complaints . You might a need a Chest X ray and Pulmonary Function Test for further evaluation .