Acute viral nasopharyngitis, often known as the common cold, is a viral infectious disease of the upper respiratory system (nose and throat). Symptoms include sneezing, sniffling, runny nose, nasal congestion, scratchy, sore, or phlegmy throat, coughing, headache, and tiredness. In severe and rare cases, symptoms of conjunctivitis (red, itchy, or watery eyes) may also accompany a cold. Those affected may also feel achy. Colds typically last five to seven days, with residual coughing and/or catarrh lasting up to one to two weeks. The common cold is the most common of all human diseases infecting adults at an average rate of 2–4 infections per year, and school-aged children as many as 12 times per year. Children and their parents or caretakers are at a higher risk, possibly due to the high population density of schools and because transmission to family members is highly efficient.
The common cold belongs to the upper respiratory tract infections. It is different from influenza, a more severe viral infection of the respiratory tract that shows the additional symptoms of rapidly rising fever, chills, and body and muscle aches. While the common cold itself is rarely life-threatening, its complications, such as pneumonia, can be.
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Symptoms |
Symptoms usually begin within 2 to 3 days after infection. The first indication of a cold is often a sore or scratchy throat. Other common symptoms are runny nose or congestion, sneezing and cough. These are sometimes accompanied by muscle aches, fatigue, and weakness. Colds rarely cause fever or headache, and never lead to extreme exhaustion. (These latter symptoms are more usual in influenza, and can differentiate the two infections.) The symptoms of a cold usually resolve after about one week, but can last up to 14 days, with a cough lasting longer than other symptoms. Symptoms may be more severe in infants and young children, and may include fever.
Between one-third and one-half of all people exposed to a cold virus become infected; 75% of the infected population show symptoms, which start 1–2 days after infection.
After a common cold, a sufferer develops immunity to the particular virus. This immunity offers only limited protection against the many other cold viruses. The person, therefore, can easily be infected by a different cold virus.
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Treatment |
As there is no medically proven and accepted medication directly targeting the causative agent, there is no cure for the common cold. Treatment is limited to symptomatic supportive options, maximizing the comfort of the patient, and limiting complications and harmful sequelae. The most reliable treatment is a combination of fluids and plenty of rest.
The common cold is self-limiting, and the host's immune system effectively deals with the infection. Within a few days, the body's humoral immune response begins producing specific antibodies that can prevent the virus from infecting cells. Additionally, as part of the cell-mediated immune response, leukocytes destroy the virus through phagocytosis and destroy infected cells to prevent further viral replication. In healthy, immunocompetent individuals, the common cold resolves in seven days on average.
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