The common cold is a respiratory infection caused by one of more than 200 different cold viruses. The most common cold viruses are rhino virus, coronavirus, adenovirus, respiratory syncytial virus, and parainfluenza virus. Symptoms start about two days after infection and include watery eyes and nose, nasal congestion, sneezing, cough, sore throat, headache, and low-grade fever.
Most people recover within a week, but cough and a runny nose can last up to two weeks.
High fever, ear pain, swollen glands, sinus pain, and serious mucus-producing cough may be signs of a bacterial infection that sometimes sets in while fighting a cold and should be seen by a physician. The average child has six to eight colds a year. According to the National Institute of Allergy and Infectious Diseases, colds cause more than 20 million lost days from school annually. Several different types and combinations of cold medications are available. Antihistamines cause drowsiness.