The common cold is caused by a viral infection of the upper respiratory tract (nose and throat). Over 200 viruses may cause the symptoms of a cold with the most common cause being a virus known as the "rhinovirus." Viruses are highly contagious and can be easily spread.
A virus can be spread through droplets in the air, that is, when someone sneezes or talks; but it can also spread by hand-to-hand contact from another person who is infected, that is, from door knobs, telephones, or by shaking hands.
What are the symptoms?
Symptoms may appear anywhere from 1 to 4 days after being infected with a virus. They last an average of 7 to 11 days, but may last up to 14 days.
Common signs and symptoms of a cold include:
- Runny or stuffy nose
- Sore throat
- Low-grade fever (up to 102 F)
Oftentimes, it is difficult to differentiate between the symptoms of the common cold and the flu. The common cold and the flu are both respiratory tract infections, but are caused by different viruses. It may be difficult to determine if you have a cold verses the flu based on symptoms alone. In general, the flu is much worse than the common cold. Flu symptoms usually develop suddenly (within hours) and are more intense. Symptoms of the flu consist of high-grade fever (102-104 F), headache, body aches, extreme tiredness, and possibly a dry cough.
What can you do to prevent a cold?
The Centers for Disease Control and Prevention (CDC) states that the simple act of hand washing is the single most important measure in preventing the spread of viral and bacterial infections.
Other ways to stop the spread of germs include:
- covering your mouth when sneezing and coughing
- avoiding contact with your eyes, nose, and mouth
- avoiding long, close contact with anyone who has a cold
- not sharing items such as drinking cups or eating utensils
How do you best treat a cold?
There is no proven cure for the common cold except time. However, getting plenty of rest, gargling with warm salt water, and drinking plenty of fluids may help you feel better sooner.
In addition, there are many over-the-counter (OTC) medications that may help relieve your symptoms. Check with your pharmacist before taking any product to make sure it is appropriate for you. For example, if you have high blood pressure you should avoid using products that contain decongestants; if you are a diabetic it is important to avoid cough syrups that contain sugar and high amounts of alcohol.
The following are general categories of OTC medications that might help provide relief of symptoms:
- Antihistamines, such as loratadine (Claritin), cetirizine (Zyrtec), and diphenhydramine (Benadryl) may help relieve symptoms of runny nose, sneezing, and watery eyes that can be associated with the common cold. Be aware that some of these agents, such as diphenhydramine, may cause drowsiness.
- Decongestants, such as pseudoephedrine (Sudafed) and phenylephrine (Sudafed PE), will help unclog a stuffy nose. Decongestants are also available as nasal sprays and drops (such as Afrin or Neo-Synephrine). However, they should not be used for more than 3 days because they can actually make your congestion worse. These products are OTC, but those containing pseudoephedrine are located behind the counter at pharmacies.
- Expectorants include products that contain guaifenesin, such as Mucinex and Robitussin. These products will help loosen mucus to make it easier to cough up.
- Antitussives, also known as cough suppressants, will aid in quieting a cough. Look for products that contain dextromethorphan, such as Delsym.
- Pain medications, such as aspirin,* acetaminophen (Tylenol), and non-steroidal anti-inflammatory drugs like ibuprofen may be used for headache, fever, or minor aches and pains.
*Do not give aspirin to children under the age of 18 with symptoms of a cold or flu. The result may be a rare condition called Reye syndrome.
Are home remedies effective in preventing and treating your cold symptoms?
There are many nontraditional and alternative therapies that are used for the prevention and treatment of the common cold. These include vitamin C, zinc, and Echinacea.
- Vitamin C
Many people believe that taking vitamin C at the onset of symptoms might help prevent a cold. However, contrary to this popular belief, research has found little proof that vitamin C has any effect on the common cold. Vitamin C is essential to keep our bodies strong and healthy, but there is little evidence that it actually prevents or treats the common cold.
A 2007 extensive review published by the Cochrane Database of Systematic Reviews, evaluated whether 200 mg or more of vitamin C reduced the incidence, duration or severity of the common cold when used either before symptoms occurred or after the onset of symptoms. The study found that vitamin C did little to reduce incidence, length, or severity of colds in the normal population. However, researchers have found that vitamin C may be beneficial in reducing the occurrence of colds for people who are exposed to brief periods of severe physical exercise or cold environments (i.e. soldiers, marathon runners, skiers).
There is some evidence that suggests the use of zinc (taken via nasal sprays or lozenges) may reduce the length and severity of cold symptoms; while other studies have reported no benefit with the use of zinc for the common cold. It is important to beware that many users of zinc nasal gel have experienced permanent loss of smell. Therefore, due to the side effects and inconsistent study results, zinc is generally not recommended for the prevention or treatment of a cold.
Echinacea is one of the most popular herbal products often used to prevent and treat the common cold. But despite its popularity, its effectiveness has been debated. Several studies have reported mixed results for the use of Echinacea in the common cold. For example, some studies have shown that it can relieve cold symptoms or shorten the length of a cold. On the other hand, two well-conducted studies found no benefit from Echinacea for the common cold. Further studies are needed to assess the effectiveness of Echinacea for the common cold.
An important note for persons who take Echinacea: people should not take Echinacea for more than eight weeks at a time due to the potential of suppressing the immune system.
Will antibiotics help treat a cold?
Do you ask your doctor for an antibiotic every time you are sick with a cold? A recent study by the CDC, found that if people think they are sick enough to see a doctor, they are sick enough to receive antibiotics. However, antibiotics will not treat the common cold, because the cause is from a virus, not from bacteria. Inappropriate use of antibiotics may contribute to the increasing problem of antibiotic-resistance bacteria (the bacteria is no longer affected by antibiotics).
When should I seek medical attention from my doctor?
Symptoms of the common cold usually resolve on their own in 7 to 10 days, but may last up to two weeks. However, you should make an appointment to see a doctor if worsening of symptoms or if any of the following occur: cold symptoms last longer than 2 weeks, difficulty breathing or chest pain, sore throat without a runny nose or a cough, fever above 103 F, earache, inability to keep food or liquids down, or unusual tiredness.
What's the bottom line?
Taking preventative action is the best defense against getting the common cold. Proper hygiene, including frequent hand-washing is still the most effective way to prevent the common cold. Following other preventable measures can also reduce your risk of the common cold. However, if you were to catch a cold, there are many OTC products that may aid in symptom relief--ask your pharmacist to help you select the most appropriate OTC products to treat your cold. Finally, it is important to remember that there is no cure for the common cold, except time.
1. Cold and Flu Guidelines: The Common Cold. American Lung Association. 2008. Available at: http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35873. Accessed January 2009.
2. Douglas RM, Hemila H, et al. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev 2007;(3):CD000980.
3. Mayo foundation for Medical Education and Research. Common Cold. Available at: http://www.mayoclinic.com/print/common-cold/DS00056/METHOD=print&DSECTION=all. Accessed January 2009.
4. MedlinePlus. Common cold. Updated January 2009. Available at: http://www.nlm.nih.gov/medlineplus/commoncold.html. Accessed January 2009.
5. Salcido A. Newer insights into the prevention of the common cold. U.S. Pharmacist. 2007. Available at: http://www.uspharmacist .com. Accessed January 2009.
6. Simasek M, Blandino D. Treatment of the Common Cold. American Family Physician. 2007; 75 (4); p. 515-520.
7. Turner RB, Bauer R, et al. An evaluation of Echinacea angustifolia in experimental rhinovirus infections. N Engl J Med 2005;353:341-8.
8. Yale SH, Liu K. Echinacea purpurea therapy for the treatment of the common cold: a randomized, double-blind, placebo-controlled clinical trial. Arch Intern Med 2004;164:1237-41.