in & around Frequent Colds

The common cold (also known as nasopharyngitis, acute viral rhinopharyngitis, acute coryza, or a cold) (Latin: rhinitis acuta catarrhalis) is a viral infectious disease of the upper respiratory system, caused primarily by rhinoviruses and coronaviruses. Common symptoms include a cough, sore throat, runny nose, and fever. Collectively, colds, influenza, and other upper respiratory tract infections (URTI) with similar symptoms are included in the diagnosis of influenza-like illness. The traditional folk theory is that a cold can be "caught" by prolonged exposure to cold weather such as rain or winter conditions, which is where the disease got its name. Common colds are seasonal in temperate latitudes, with more occurring during winter. The experimental evidence for this effect is uneven: many experiments have failed to produce evidence that short-term exposure to cold weather or direct chilling increases susceptibility to infection, implying that the seasonal variation is instead due to a change in behaviors such as increased time spent indoors at close proximity to others. However, other experiments do find such an effect for both body chilling and cold air exposure, and a number of mechanisms by which lower temperatures could compromise the immune system have been suggested, while other experiments have shown that exposure to cold temperatures may instead stimulate the immune system.