Hello, Most commonest causes for cold cough is -Bad Immunity others are Change or fluctuation in weather conditions which in turn results or favours growth of various varities of virsus,Viral infections of throat,exposure to too cold climate ,sudden exposure to cold then entering a well heated rooms or so ,exposure to dust and pollans,exessive exposure with people who are already infected with the problems are more because of poor ventilation and extremes of climate ,staying in an room where there is poor air circulation ,or in a room with heaters or Air conditioner on for whole day So thus the list goes on. In ayurveda the cause for your problem is excessive Cough inside your body . you can try take a hot vapour of water with ecalyptus oil ,or any vapouriser added to boiling water and take a steam for about 5-10 min .This will dilate the bronchus and the blocks in the nose.Helps in nasal congestion too. Drink fresh Vit C Juice everyday in your life to improve immunity. Finely minced ginger and take out the 1-2 tsf juice mixed with 2tsf of honey is really a good remedy in case of severe cough.take it every 3-4 hrs in a day .Sip luke warm water. you ll see the difference without taking antibiotics cold will get better in 1-3 days.if you have fever, body aches do consult your Doctor . wish you speedy recovery.