The common cold (viral upper respiratory tract infection (VURI), acute viral rhinopharyngitis, acute coryza, or cold) is a contagious, viral infectious disease of the upper respiratory system, caused primarily by rhinoviruses and corona viruses. Common symptoms include a sore throat, runny nose, and fever. There is no cure; however, symptoms usually resolve spontaneously in 7 to 10 days, with some symptoms possibly lasting for up to three weeks.
The common cold is the most frequent infectious disease in humans with on average two to four infections a year in individual adults and up to 6 - 12 in individual children. Collectively, colds, influenza, and other infections with similar symptoms are included in the diagnosis of influenza-like illness. They may also be termed upper respiratory tract infections (URTI). Influenza involves the lungs while the common cold does not.
Symptoms are cough, sore throat, runny nose, and nasal congestion; sometimes this may be accompanied by conjunctivitis ( pink eye ), muscle aches, fatigue, headaches, shivering, and loss of appetite. Fever is often present thus creating a symptom picture which overlaps with influenza. The symptoms of influenza, however, are usually more severe. The common cold usually resolves spontaneously in 7 to 10 days, but some symptoms can last for up to three weeks. In children, the cough lasts for more than 10 days in 35-40% and continue for more than 25 days in 10%.
Those suffering from colds often report a sensation of chilliness even though the cold is not generally accompanied by fever, and although chills are generally associated with fever, the sensation may not always be caused by actual fever. In one study, 60% of those suffering from a sore throat and upper respiratory tract infection reported headaches, often due to nasal congestion.