A cold is a contagious viral infection of the upper respiratory tract characterized by inflammation (swelling and irritation with presence of extra immune cells) of the mucous membranes, sneezing, and sore throat.
Alternative Names
Viral upper respiratory infection; Common cold
Causes, incidence, and risk factors
Colds are caused by more than 200 different viruses known as rhinoviruses. They are not caused by the same viruses responsible for influenza ("the flu"). Colds spread through exposure to droplets from the coughing or sneezing of others with a cold or by hand contact with objects contaminated by someone with a cold. The incidence of colds is highest among children, and the incidence decreases with age because immunity to the virus causing the cold occurs after the illness. Gradually, immunity to a wide variety of viruses that cause colds is developed in adults. On average, children have 10 colds a year and adults have 3.
Signs and tests
Diagnosis is based on the clinical symptoms.
Treatment
Cold symptoms should go away in a week to 10 days. Treatment by a health care provider is not necessary unless symptoms continue, or existing respiratory conditions are worsened by the symptoms.
Home care measures may relieve some of the symptoms of the cold but will not affect the duration of the illness. These measures include taking over-the-counter pain relievers , drinking plenty of fluids, and rest. Antibiotics are not appropriate treatment for colds.
Expectations (prognosis)
Symptoms usually go away in 7 to 10 days.
Calling your health care provider
Use home care measures first. Call for an appointment with your health care provider if symptoms worsen or do not improve after 7 to 10 days, if breathing difficulty develops, or if thick green or brown sputum develops.
Prevention
There is no scientific evidence to support beliefs that avoiding cold temperatures or drafts or taking large quantities of vitamin C will prevent colds.