When is the common cold most contagious?

The common cold is most contagious during the first two to four days after symptoms appear, states About.com. Common cold symptoms include a runny nose, congestion, sore throat, cough and sneezing, notes MedlinePlus. The common cold virus spreads through the air and on surfaces.

Although colds are contagious for only a few days after infection, the virus can live in the body for up to three weeks, explains About.com. Medical attention is usually not required for a cold, but if it comes with a fever over 100 degrees Fahrenheit, sinus pain, sweating and chills, or swollen glands, medical attention is recommended, notes Mayo Clinic.