Let us understand, that under viral attack, cells in the mucus membranes of the nose release histamine, blood capillaries in the area dilate, and blood serum leaks into the tissues of the membrane. The membrane swells.
Some of its tissues secrete more mucus, not all of which can move up through the constricted nasal passages. The excess simply runs out. An overload of mucus in the throat excites nerve endings that stimulate a cough, which clears the passage before the virus-laden mucus can move down into the lungs.
The swelling and cell damage stimulates receptors in the nose, triggering a sneeze. Your head feels stuffy and congested, your nose runs your throat is sore.
Each sneeze and cough releases outside the body a spray of droplets loaded with virus particles in an attempt to heal the body from the cold.
Amazing Isn’t it?