Common cold

Common cold

The common cold (acute viral rhinopharyngitis, acute coryza, viral upper respiratory tract infection, or a cold) is a contagious, viral infectious disease of the upper respiratory system, primarily caused by rhinoviruses, (picornaviruses) or coronaviruses. It is the most common infectious disease in humans;[1] there is no known cure, but it is very rarely fatal.

Collectively, colds, influenza, and other infections with similar symptoms are included in the diagnosis of influenza-like illness. Often, influenza and the common cold are mistaken for each other, even by professional healthcare workers, but most of the recommended home treatments (drinking plenty of warm fluids, keeping warm, etc.) are similar if not the same. The symptoms of influenza often include a fever and are more severe than the cold.

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[2] but are more severe.[3] 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.[2] In one study, 60% of those suffering from a sore throat and upper respiratory tract infection reported headaches[2], 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.[4]

Complications:
The common cold can lead to opportunistic coinfections or superinfections such as acute bronchitis, bronchiolitis, croup, pneumonia, sinusitis, otitis media, or strep throat. People with chronic lung diseases such as asthma and COPD are especially vulnerable. Colds may cause acute exacerbations of asthma, emphysema or chronic bronchitis.[5]

Cause and susceptibility:
The common cold is most often caused by infection with one of the 99 known serotypes of rhinovirus, a type of picornavirus.[6][7] Around 30-50% of colds are caused by rhinoviruses.[2] Other viruses causing colds are coronavirus (causing 10-15%[2]), human parainfluenza viruses, human respiratory syncytial virus, adenoviruses, enteroviruses, or metapneumovirus.[8] 5-15% are caused by influenza viruses.[2] In total over 200 serologically different viral types cause colds.[2] Coronaviruses are particularly implicated in adult colds. Of over 30 coronaviruses, 3 or 4 cause infections in humans, but they are difficult to grow in the laboratory and their significance is thus less well-understood.[8] Due to the many different types of viruses and their tendency for continuous mutation, it is impossible to gain complete immunity to the common cold.

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.[9]

Vitamin D: A 2009 study found that low blood serum levels of vitamin D were associated with increased rates of the common cold.[10] A randomized controlled trial found that 104 post-menopausal African American women living in New York given vitamin D were three times less likely to report cold and flu symptoms than 104 placebo controls. A low dose (800 IU/day) not only reduced reported incidence, it abolished the seasonality of reported colds and flu. A higher dose (2000 IU/day), given during the last year of the trial, virtually eradicated all reports of colds or flu.[11]

Prevention:

The best way to avoid a cold is to wash hands thoroughly and regularly; and to avoid touching the eyes, nose, mouth, and face. Anti-bacterial soaps have no extraordinary effect on the cold virus; it is the mechanical action of hand washing with the soap that removes the virus particles.[26] Rhinoviruses can live up to 3 hours outside the body on the skin or objects.[8]

In 2002, the Centers for Disease Control and Prevention recommended alcohol-based hand gels as an effective method for reducing infectious viruses on the hands of health care workers.[27] As with hand washing with soap and water, alcohol gels provide no residual protection from re-infection.

The common cold is caused by a large variety of viruses, which mutate quite frequently during reproduction, resulting in constantly changing virus strains. Thus, successful immunization is highly improbable.

Treatment:

The common cold usually resolves spontaneously in 7 to 10 days, but some symptoms can last for up to three weeks.[4] There are no medications or herbal remedies proven to shorten the duration of illness. Treatment is symptomatic support usually via providing analgesics for fever, headache and myalgia, nasal decongestants and antihistamines for nasal congestion and runniness, and lozenges for sore throat.

Conservative management: The National Institute of Allergy and Infectious Diseases suggests getting plenty of rest, drinking fluids to maintain hydration, gargling with warm salt water, using cough drops, throat sprays, or over-the-counter pain or cold medicines.[8] Saline nasal drops may help alleviate congestion.[28]

Treatments that may help alleviate symptoms include analgesics, decongestants, and cough suppressants,[citation needed] first-generation antihistamines such as brompheniramine, chlorpheniramine, diphenhydramine and clemastine (which reduce mucus gland secretion and thus combat blocked/runny noses but also may make the user drowsy). Second-generation antihistamines do not have a useful effect on colds.[citation needed]

Vitamin C in normal or mega doses has not been shown to be beneficial in a normal population for the prevention or treatment of the common cold. It however might be beneficial in people exposed to periods of severe physical exercise or cold environments.[29]

Various cold medicines exist however little evidence suggest they are any more effective than simple analgesics. They include antitussives, antihistamines and decongestants usually in combination with an analgesic. They are not recommended for use in children because evidence does not support their effectiveness and there are concerns of harm.[30]

Antibiotics: Antibiotics only target bacteria and thus do not have any beneficial effect against the common cold.

Antivirals: There are no approved antiviral drugs for the common cold.

Alternative treatments: Many alternative treatments are used to treat the common cold. None, however, are supported by solid scientific evidence.[25] 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.[31][32] Other alternative treatments which similarly lack solid scientific evidence include calendula[33], ginger[34], garlic[35] and vitamin C supplements.[36]

Common cold
Heart Murmur Adenoids Bursitis Eye Infections Hepatitis C Glomerulonephritis (GN) Male And Female Infertility - Causes Escherichia Coli O157 Clostridium Epstein-Barr virus Cervical cancer Allergy-Immunology Glossary Mumps Cancer Head And Neck Blood Coagulation Disorders Sickle-Cell Disease Gastrointestinal Disorders Common cold Warts - Causes, Symptoms, And Treatment What Causes Acne Clarithromycin Leishmania Infection Angiostrongylus Infection Tuberculosis Addison's disease Coming Soon Headaches And Allergies Hay fever Hand, Foot, & Mouth Disease Pubic Lice Infestation Psoriasis Protein Suppresses Allergy Prostate Cancer Prenatal Testing Prader-Willi Syndrome Post-Traumatic Stress Disorder (PTSD) Poison Plants Pneumococcal Disease Plague Pet Allergy Penicillin Allergy Patent Ductus Arteriosus (PDA) Polio Disease Pinworm Infection Pheochromocytoma Phenylketonuria Pertussis Disease PAD (Peripheral Arterial Disease) Peanut Allergy Symptoms Parvovirus B19 (Fifth Disease) Pacemaker	Common cold The common cold (acute viral rhinopharyngitis, acute coryza, viral upper respiratory tract infection, or a cold) is a contagious, viral infectious disease of the upper respiratory system, primarily caused by rhinoviruses, (picornaviruses) or coronaviruses. It is the most common infectious disease in humans;[1] there is no known cure, but it is very rarely fatal. Collectively, colds, influenza, and other infections with similar symptoms are included in the diagnosis of influenza-like illness. Often, influenza and the common cold are mistaken for each other, even by professional healthcare workers, but most of the recommended home treatments (drinking plenty of warm fluids, keeping warm, etc.) are similar if not the same. The symptoms of influenza often include a fever and are more severe than the cold. 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[2] but are more severe.[3] 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.[2] In one study, 60% of those suffering from a sore throat and upper respiratory tract infection reported headaches[2], 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.[4] Complications: The common cold can lead to opportunistic coinfections or superinfections such as acute bronchitis, bronchiolitis, croup, pneumonia, sinusitis, otitis media, or strep throat. People with chronic lung diseases such as asthma and COPD are especially vulnerable. Colds may cause acute exacerbations of asthma, emphysema or chronic bronchitis.[5] Cause and susceptibility: The common cold is most often caused by infection with one of the 99 known serotypes of rhinovirus, a type of picornavirus.[6][7] Around 30-50% of colds are caused by rhinoviruses.[2] Other viruses causing colds are coronavirus (causing 10-15%[2]), human parainfluenza viruses, human respiratory syncytial virus, adenoviruses, enteroviruses, or metapneumovirus.[8] 5-15% are caused by influenza viruses.[2] In total over 200 serologically different viral types cause colds.[2] Coronaviruses are particularly implicated in adult colds. Of over 30 coronaviruses, 3 or 4 cause infections in humans, but they are difficult to grow in the laboratory and their significance is thus less well-understood.[8] Due to the many different types of viruses and their tendency for continuous mutation, it is impossible to gain complete immunity to the common cold. 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.[9] Vitamin D: A 2009 study found that low blood serum levels of vitamin D were associated with increased rates of the common cold.[10] A randomized controlled trial found that 104 post-menopausal African American women living in New York given vitamin D were three times less likely to report cold and flu symptoms than 104 placebo controls. A low dose (800 IU/day) not only reduced reported incidence, it abolished the seasonality of reported colds and flu. A higher dose (2000 IU/day), given during the last year of the trial, virtually eradicated all reports of colds or flu.[11] Prevention: The best way to avoid a cold is to wash hands thoroughly and regularly; and to avoid touching the eyes, nose, mouth, and face. Anti-bacterial soaps have no extraordinary effect on the cold virus; it is the mechanical action of hand washing with the soap that removes the virus particles.[26] Rhinoviruses can live up to 3 hours outside the body on the skin or objects.[8] In 2002, the Centers for Disease Control and Prevention recommended alcohol-based hand gels as an effective method for reducing infectious viruses on the hands of health care workers.[27] As with hand washing with soap and water, alcohol gels provide no residual protection from re-infection. The common cold is caused by a large variety of viruses, which mutate quite frequently during reproduction, resulting in constantly changing virus strains. Thus, successful immunization is highly improbable. Treatment: The common cold usually resolves spontaneously in 7 to 10 days, but some symptoms can last for up to three weeks.[4] There are no medications or herbal remedies proven to shorten the duration of illness. Treatment is symptomatic support usually via providing analgesics for fever, headache and myalgia, nasal decongestants and antihistamines for nasal congestion and runniness, and lozenges for sore throat. Conservative management: The National Institute of Allergy and Infectious Diseases suggests getting plenty of rest, drinking fluids to maintain hydration, gargling with warm salt water, using cough drops, throat sprays, or over-the-counter pain or cold medicines.[8] Saline nasal drops may help alleviate congestion.[28] Treatments that may help alleviate symptoms include analgesics, decongestants, and cough suppressants,[citation needed] first-generation antihistamines such as brompheniramine, chlorpheniramine, diphenhydramine and clemastine (which reduce mucus gland secretion and thus combat blocked/runny noses but also may make the user drowsy). Second-generation antihistamines do not have a useful effect on colds.[citation needed] Vitamin C in normal or mega doses has not been shown to be beneficial in a normal population for the prevention or treatment of the common cold. It however might be beneficial in people exposed to periods of severe physical exercise or cold environments.[29] Various cold medicines exist however little evidence suggest they are any more effective than simple analgesics. They include antitussives, antihistamines and decongestants usually in combination with an analgesic. They are not recommended for use in children because evidence does not support their effectiveness and there are concerns of harm.[30] Antibiotics: Antibiotics only target bacteria and thus do not have any beneficial effect against the common cold. Antivirals: There are no approved antiviral drugs for the common cold. Alternative treatments: Many alternative treatments are used to treat the common cold. None, however, are supported by solid scientific evidence.[25] 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.[31][32] Other alternative treatments which similarly lack solid scientific evidence include calendula[33], ginger[34], garlic[35] and vitamin C supplements.[36]
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