The Common Cold

What's up with the common cold? I mean I just got over one last week and now it seems like another is hitting me. The last several years I escaped the common cold and considered myself pretty healthy. So I did a little reading...

Thanks to Wikipedia, I learned:

Symptoms:

Common symptoms are cough, 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 (due to their immune system not being fully developed) as well as the elderly (due to their immune system often being weakened).

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. The symptoms of a cold usually resolve after about one week; however, it is not rare that symptoms last up to three weeks.

What I thought the cold virus looks like

Causes:

Viruses

The common cold is most often caused by infection with one of the 99 known serotypes of rhinovirus, a type of picornavirus.Around 30-50% of colds are caused by rhinoviruses.

Sleep

Lack of sleep has been associated with the common cold. Those who sleep fewer than 7 hours per night were three times more likely to develop an infection when exposed to a rhinovirus when compared to those who sleep more than 8 hours per night.

Vitamin D

People with the lowest blood vitamin D levels reported having significantly more recent colds or cases of the flu. The risks were even higher for those with chronic respiratory disorders, such as asthma and emphysema.

Cold weather

An ancient belief still common today claims 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. Although common colds are seasonal, with more occurring during winter, experiments so far 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.

Humidity

Humidity is also believed to play a role in viral transmission. One theory is that dry air causes evaporation of water and smaller viral droplets that disperse farther and stay in the air longer.

What the cold virus (rhinovirus) really looks like.