Acute viral rhinopharyngitis, or acute coryza, usually known as the common cold, is a contagious, viral infectious disease of the upper respiratory system, primarily caused by picornaviruses (including rhinoviruses) or coronaviruses. It is the most common infectious disease in humans; there is no known cure. The symptoms of a cold usually resolve after about one week, but can last up to three weeks.

Collectively, colds, influenza, and other infections with similar symtoms are included in the diagnosis of influenza-like illness.

Symptoms

Common symptoms are sore throat, runny nose, nasal congestion, and sneezing; sometimes accompanied by 'pink eye', muscle aches, fatigue, malaise, headaches, muscle weakness, uncontrollable shivering, loss of appetite, and rarely extreme exhaustion. Fever is more commonly a symptom of influenza, another viral upper respiratory tract infection (URTI) whose symptoms broadly overlap with the cold but are more severe. Symptoms may be more severe in infants and young children.

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.

The symptoms of a cold usually resolve after about one week, but can last up to three weeks.

No cure

Although the disease is generally mild and self-limiting, patients with common colds often seek professional medical help, use over-the-counter drugs, and may miss school or work days. The annual cumulative societal cost of the common cold in developed countries is considerable in terms of money spent on remedies, and hours of lost productivity.

There are no antiviral drugs approved to treat or cure the infection; all medications used are palliative and treat symptoms only. Alternative treatments such as vitamin C, echinacea, and zinc have been proposed but none of them have been shown to decrease the duration of the illness, and thus none of them are approved by the Food and Drug Administration or European Medicines Agency. To prevent infection, washing or disinfectingFact: date=April 2009 hands has been found effective, as this minimizes person-to-person transmission of the virus.

Progression of disease

After initial infection, the viral replication cycle begins within 8 to 12 hours. Symptoms can occur shortly thereafter, and usually begin within 2 to 5 days after infection, although occasionally in as little as 10 hours after infection. The first indication of a cold is often a sore or scratchy throat. Other common symptoms are runny nose, congestion, and sneezing. These are sometimes accompanied by muscle aches, fatigue, malaise, headache, weakness, or loss of appetite. Cough and fever generally indicate influenza rather than the cold with a positive predictive value of around 80%. Influenza is also sudden onset whereas with the cold symptoms increase over time and peak in 2-3 days.