👉 Sneezing is a respiratory movement that occurs when the nose and throat are blocked by mucus, allergens or other irritants. It can be caused by various factors such as pollen, dust, cat hair, smoke, or cold air. The act of sneezing involves forcefully blowing your nose to clear out the mucus in your nasal passages. This is a common symptom that helps you feel better after exposure to allergens or irritants.