CauseThe common cold is caused by a virus, usually a rhinovirus, that enters your body through the nose, mouth, or eyes.It spreads through airborne droplets when someone coughs or sneezes, or by touching contaminated surfaces.EffectOnce infected, you may experience:Runny or stuffy noseSneezing and coughingSore throatMild headache or body painLow-grade feverFeeling weak or tiredThe virus irritates your respiratory system, which leads to the symptoms we feel when we catch a cold.