I've had this problem for years, thicknes(mucus) in the throat, non productive etc.Always hacking and coughing, in the day time, not at night! Lungs clear... As a last resort my gp thought it might be allergy related and suggested tablets for the relief of. Rather than going back to gp all the time, I now buy Piriton or Piriteeze (spelling?) from Boots which have the same ingredients as those gp prescribed. But they are a bit pricey. Equally effective are Tescos own brand of anti allergy tablets, but make sure they heve the right ingredients and are non drowsy. They work for me .Shirleyc1941