The common cold is not, in itself, a disease. It is a health issue that can be caused by more than 200 different viruses that are commonly spread through close contact. One can also contract it through the air from infected individuals’ coughs and sneezes. While colds caused by viral illnesses may cause minor discomfort and mostly clear up within 7 to 10 days, they can lead to other health issues. These illnesses are called secondary infections, including ear infections, pneumonia, bronchitis, and sinus infection, to name just a few.