The common cold is a viral infectious disease of the upper respiratory system, primarily caused by rhinoviruses, (picornaviruses) or rhinoviruses,. It is the most common infectious disease in humans, there is no known cure, but it is very rarely fatal.

It is  mostly  recommended for home treatments (drinking plenty of warm fluids, keeping warm, etc.)

common symptoms are

sore throat, runny nose ,nasal congestion and sneezing , sometimes accompanied by  pink eye ,muscle aches, fatigue, malaise ,headache  and muscle weakness. Fever is more commonly a symptom of influenza.

complications

The common cold can lead to opportunistic coinfections  or superinfections  such as acute bronchitis , bronchiolitis, pneumonia, sinusitis , and  otitis media. People with chronic lung diseases such as asthma  and COPD are especially vulnerable. Colds may cause acute exacerbations of asthma , empysema  or chronic bronchitis

causes

viruses

rhinoviruses, (picornaviruses) or coronaviruses.

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.  vitamin D can be recommended to prevent colds and flu.

cold weather

By prolonged exposure to cold weather such as rain or winter conditions  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.

With respect to the causation of cold-like symptoms, researchers at the Common Cold Centre at Cardiff University  conducted a study to “test the hypothesis that acute cooling of the feet causes the onset of common cold symptoms.The study measured the subjects’ self-reported cold symptoms, and belief they had a cold, but not whether an actual respiratory infection developed. It found that a significantly greater number of those subjects chilled reported cold symptoms 4 or 5 days after the chilling. In particular, 13 of the 90 chilled subjects reported having a cold 4 or 5 days after the study, in contrast to 5 of the 90 control subjects reporting the same (p-value was 0.047). The study concluded that the onset of common cold symptoms can be caused by acute chilling of the feet. One possible explanation postulated by past researchers is that, during the cold season, “many people are mildly infected but show no symptoms,” but “if they become chilled, this causes a pronounced constriction of the blood vessels in the nose and shuts off the warm blood that supplies the white cells that fight infection. Although the chilled subject believes they have ‘caught a cold’ what has, in fact, happened is that the dormant infection has taken hold.”[19]. However, this explanation has not been scientifically verified.

Another possibility which remains to be explored involves the role that proteins of the complement system play in the prevention of a sustained infection. Decreased temperature may result in a drop in tissue permeability and, as a result, may lead to reduced plasma leakage. Among the many proteins suspended in plasma are complement proteins (e.g. C3) which serve to disable, destroy, or tag for destruction foreign particulate (in this case viral capsids). Thus, sustained exposure to cold may inhibit the effectiveness of the complement system and allow the virus a better chance of establishing a state of infection.[citation needed]

ICAM-1, the receptor that Rhinovirus binds to in order to infect cells, is known to increase in number and receptiveness in response to many irritants, including dust and pollen. That a cold climate in combination with varying degrees of humidity can act as a similar “irritant” needs to be investigated

Prevention

The best way to avoid a cold is thorough and regular washing of the hands. This resulted in a 16% decrease in the rate of respiratory infections and as much as a 20% decrease in the common cold.Anti-bacterial and non anti-bacterial soaps are equally effective. Alcohol-based hand sanitizers also reduce viruses significant and are recommended as a method in health care environments. The use of alcohol based hand gels in the home reduced rate of transmission of respiratory illnesses among family members.

Probiotics in children 3 – 5 years old were found effective in decreases cold symptoms when taken over 6 months.

Developing a vaccine for the common cold has been unsuccessful. This is due to a number of reasons including: a large variety of viruses and the fact that they mutate rapidly. Many thus believe that successful immunization is highly improbable.

Management

“Consult your Physician” for treatment of the common cold

There are no medications or herbal remedies proven to shorten the duration of illness. Treatment is symptomatic support usually via analgesics for fever, headache and myalgia, nasal decongestants, and lozenges for sore throat.

The common cold usually resolves spontaneously in 7 to 10 days, but some symptoms can last for up to three weeks. A history of smoking extends the duration of illness about three days.

Conservative

Treatments that help alleviate symptoms include simple analgesics and antipyretics such as ibuprofen and acetaminophen / paracetamol.

Evidence does not show that cold medicines are any more effective than simple analgesics. They are not recommended for use in children due to no evidence supporting their effectiveness and the potential of harm.

Getting plenty of rest, drinking fluids to maintain hydration, gargling with warm salt water, or use of over-the-counter pain medicines are reasonable conservative measures. Saline nasal drops may help alleviate nasal congestion.

Evidence for encouraging the active intake of fluids in acute respiratory infections is lacking as is the use of heated humidified air.

Antibiotics and antivirals

amtibiotics are not effective against the viruses that causes the common cold and due to their side effects cause overall harm. There are no approved anti viral drugs  for the common cold even though some preliminary research has shown benefit

Alternative treatments

Alternative treatments used for the common cold

Many alternative treatments are used to treat the common cold. None however are recommended due to insufficient scientific evidence[dead link Some alternative treatments, like echinacea, have not been shown to have any effects on the frequency of infection, the duration of infection, or the severity of symptoms of the common cold. Other alternative treatments which similarly lack solid scientific evidence include calendula,ginger, garlic and vitamin C supplements.

While vitamin C in normal or increased doses has not been shown to be beneficial in a normal population for the prevention or treatment of the common cold, it might be beneficial in people exposed to periods of severe physical exercise or cold environments.

Prognosis

The common cold is generally mild and self-limiting.