The common cold can spread during any time of the year. It often spreads during the wintertime in colder environments. People stay inside more often and can spread the virus to other people more easily. In warmer climates, a cold may spread more often during the rainy season. People usually have a cold for about a week or two. Colds are most contagious for two or three days. The contagious period ends after about a week.
Rhinoviruses
Rhinoviruses are responsible for about 30 percent to 35 percent of all adult colds, according to the National Institute of Allergy and Infectious Diseases (NIAID). They're most active in the early fall, spring and summer but rarely cause serious illnesses. They usually cause the uncomfortable feelings of a runny nose, sore throat, cough, watery eyes, sneezing and congestion. The rhinovirus can thrive in temperatures found in the human nose. There are at least 110 rhinovirus types.
Coronaviruses
The coronavirus brings on colds in the winter and early spring. This virus is difficult to grow in the lab, so it's hard to determine how much of a role it plays in colds compared to other viruses.
Severe Culprits
Viruses that make up about 10 percent to 15 percent of adult colds can also cause the more severe illnesses. The influenza A and B viruses cause flu, and parainfluenza viruses can cause lower respiratory infections in adults and young children.
Contact
Viruses enter the mouth or nose to spread the cold. You can catch a cold when a sick person sneezes, coughs or even talks, spreading the cold virus in the air, the Mayo Clinic says. Shaking hands can spread a cold. Sharing utensils, towels or other items can also spread colds. You can catch a cold when you touch a person with a cold or share an object, and then touch your mouth, nose or eyes.
Children
Adults may average two to four colds a year. Children may have from six to 10 colds a year. Parents often get colds from their children. Children often get colds from other children, usually because of school or day care where the virus can quickly travel from person to person.
Cold Myths
The causes of 30 percent to 50 percent of colds are still not known, although they're believed to have viral causes, the NIAID says. Viruses that cause colds in adults may be the same viruses that cause colds in children, but it's difficult to examine the causes of colds for children in studies. You don't get a cold from cold weather, exercise, diet or enlarged tonsils or adenoids. However, stress and allergies may play a part in increasing your chances of getting a cold.
