If the mucus is clear this could be a warning sign of a tumour, and definitely time for a check up.
However, if it's thick and not the usual colour this could be a sign that you're battling a sinus infection.
Tools designed to ensure computer code in smart cars does not crash has been inspired by hungry penguins.
The rounded sleeping capsules send guests drifting into ocean before arriving on desert island by morning.
Sitting on the saddle activates the part of the brain responsible for learning, a study has claimed.
Scientists are appealing for more people to donate their brains for research after they die.
Life on Earth may have arrived from Mars on an asteroid, scientists have claimed.
Lunar mission scheduled at the end of 2017 could find out if beer can be brewed on the moon.
A bottle used to teach children how far litter can travel ended up on Scottish beach after 8,700-mile journey.