Colds are caused by a virus and can occur year-round. The common cold generally involves a runny nose, nasal congestion, and sneezing. Other symptoms include sore throat, cough, and headache. A cold usually lasts about 7 days, with perhaps a few lingering symptoms such as a cough for another week.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.