Common Cold

What is the common cold, and what causes it?

The common cold is a self-limited contagious illness that can be caused by a number of different types of viruses. The common cold is medically referred to as a viral upper respiratory tract infection. Symptoms of the common cold may include cough, sore throat, nasal congestion, runny nose, and sneezing. More than 200 different types of viruses are known to cause the common cold, with rhinovirus causing approximately 30%-35% of all adult colds. Other commonly implicated viruses include coronavirus, adenovirus, respiratory syncytial virus, and parainfluenza virus. Because so many different viruses can cause a cold and because new cold viruses constantly develop, the body never builds up resistance against all of them. For this reason, colds are a frequent and recurring problem. In fact, children in preschool and elementary school can have six to 12 colds per year while adolescents and adults typically have two to four colds per year. The common cold occurs most frequently during the fall and winter months.

The common cold is the most frequently occurring illness in the world, and it is a leading cause of doctor visits and missed days from school and work. It is estimated that individuals in the United States suffer 1 billion colds per year, with approximately 22 million days of school absences recorded annually.

How is the common cold transmitted?

The common cold is spread either by direct contact with infected secretions from contaminated surfaces or by inhaling the airborne virus after individuals sneeze or cough. Person-to-person transmission often occurs when an individual who has a cold blows or touches their nose and then touches someone or something else. A healthy individual who then makes direct contact with these secretions can subsequently become infected, often after their contaminated hands make contact with their own eyes or nose. A cold virus can live on objects such as pens, books, telephones, computer keyboards, and coffee cups for several hours and can thus be acquired from contact with these objects.

What are the symptoms and signs of the common cold in adults, children, and infants?

The symptoms of the common cold typically begin two to three days after acquiring the infection (incubation period). Symptoms and signs of the common cold vary depending on the virus responsible for the infection and may include the following

• nasal stuffiness or drainage,

• sore or scratchy throat,

• sneezing,

• hoarseness,

• cough,

• watery eyes,

• low-grade fever,

• headache,

• body aches, and

• fatigue.

The signs and symptoms of the common cold in infants and children are similar to those seen in adults. The cold may begin with a runny nose with clear nasal discharge, which later may become yellowish or greenish in color. Infants and children may also become more fussy and have decreased appetite.

The symptoms of the common cold will typically last anywhere from four to 14 days, with most individuals improving in one week.

Does it have anything to do with exposure to cold weather?

Though the common cold usually occurs in the fall and winter months, the cold weather itself does not cause the common cold. Rather, it is thought that during cold-weather months people spend more time indoors in close proximity to each other, thus facilitating the spread of the virus. For this same reason, children in day care and school are particularly prone to acquiring the common cold.

What is the difference between the common cold and influenza (the flu)?

Many people confuse the common cold with influenza (the flu). Influenza is caused by the influenza virus, while the common cold generally is not. While some of the symptoms of the common cold and influenza may be similar, patients with the common cold typically have a milder illness. Patients with influenza usually appear more ill and have a more abrupt onset of illness with fever, chills, headache, substantial muscle and body aches, dry cough, and extreme weakness.

Though differentiating between the common cold and influenza can be difficult, there is laboratory testing available to confirm the diagnoses of influenza.

How is the common cold diagnosed?

Your physician or health-care practitioner will generally diagnose the common cold based on the description of your symptoms and the findings on your physical exam. Laboratory testing and imaging studies are generally not necessary unless there are concerns about another underlying medical condition or potential complications.

What is the treatment for the common cold? Are there any home remedies for the common cold?

There is no cure for the common cold. The common cold is a self-limited illness that will resolve spontaneously with time. Home remedies and treatments are directed at alleviating the symptoms associated with the common cold while the body fights off the infection.

Home treatment for the common cold includes getting rest and drinking plenty of fluids. In older children and adults, over-the-counter medications such as throat lozenges, throat sprays, cough drops, and cough syrups may help relieve symptoms, though they will not prevent or shorten the duration of the common cold. Gargling with warm saltwater may help those with a sore throat. Decongestants such as pseudoephedrine (Sudafed) or antihistamines may be used for nasal symptoms, while saline nasal sprays may also be beneficial. It is important to note that over-the-counter medications may cause undesirable side effects, therefore they must be taken with care.

Acetaminophen (Tylenol and others) and ibuprofen (Advil, Motrin) can help with fever, sore throat, and body aches.

The treatment for infants and small children with the common cold is supportive as well. It is especially important to allow rest and encourage plenty of fluids in order to prevent dehydration. Nasal drops and bulb suctioning may be used to clear nasal mucus in infants. Medications such as acetaminophen and ibuprofen may be taken for pain or fever based on the package recommendations for age and weight. Do not use aspirin or aspirin-containing medications in children or teenagers because it has been associated with a rare, potentially fatal condition called Reye's syndrome. Finally, over-the-counter cough and cold medications for infants and children are not recommended (see WARNING below).

WARNING: The United States Food and Drug Administration (FDA) recommends that over-the-counter cough and cold medications not be used in children younger than 4 years of age because serious and potentially life-threatening side effects can occur.

Are antibiotics a suitable treatment for the common cold?

No. Antibiotics play no role in treating the common cold. Antibiotics are effective only against illnesses caused by bacteria, and colds are caused by viruses. Not only do antibiotics not help, but they can rarely also cause severe allergic reactions that can sometimes be fatal. Furthermore, using antibiotics when they are not necessary has led to the growth of several strains of common bacteria that have become resistant to certain antibiotics. For these and other reasons, it is important to limit the use of antibiotics to situations in which they are medically indicated.

Though occasionally a bacterial infection, such as sinusitis or a middle ear infection, can develop following the common cold, the decision to treat with antibiotics should be determined by your physician or health-care practitioner.

When should a physician or other health-care practitioner be consulted?

Generally, the common cold can be treated at home and managed with over-the-counter medications. However, if you develop more severe symptoms such as shaking chills, high fever (greater than 102 F), severe headache, neck stiffness, vomiting, abdominal pain, difficulty breathing, chest pain, confusion, or failure to improve after 10 days, you should consult your physician or health-care practitioner immediately. Infants 3 months of age or younger who develop a cold or fever should consult their health-care practitioner as well.

If you have a sore throat and a fever with no other cold symptoms, you should also be evaluated by your physician. This illness may be strep throat, a bacterial infection requiring treatment with antibiotics.

Finally, if you notice facial pain or yellow/green drainage from your nose accompanied by a fever, it is possible that you have a sinus infection (sinusitis) that would benefit from a medical evaluation and a possible course of antibiotics.