Ay, totoo yan, maraming kids dito na ganyan, lalo na kapag malamig gabi or may allergy. Usually it's either post-nasal drip (yung mucus from colds na dumadown sa throat), or sometimes reflux, or kahit allergens lang na nag-trigger kapag nakatulog na sila at nag-settle sa airways. One of my mum friends's daughter ganyan din, at naging okay after bumenta ng humidifier sa kwarto nila, pero better check with your pedia na lang to be sure kung may underlying cause talaga, kasi may times na kailangan ng proper treatment para ma-ease ang cough.