When the mucus produced is thicker or more in quantity than usual, it is noticed by the individual. The excess mucus that is secreted from the front of the nose causes a running nose. When the excess mucus runs down the back of the nose, the condition is called post-nasal drip. Post-nasal drip can be prevented by identifying the cause and avoiding it. Cold/refrigerated water can aggrevate the onset of nasal mucus.