A cold is an upper respiratory infection caused by a virus. Colds tend to occur most often in winter, although scientists aren't sure why. In the United States, adults usually have 2 colds per year, and children have at least 6.
There is no foolproof way to prevent a cold and no way to cure it. But you can treat the symptoms. Colds tend to last about a week, and can be accompanied by sore throat and cough. Unlike the flu, colds don't usually cause a high fever (above 102° F).
Signs and Symptoms
- Sneezing and runny nose from nasal congestion
- Sore throat
- Low-grade fever (less than 102° F)
Colds are caused by more than 100 different viruses, although most colds are caused by rhinoviruses. Young children with respiratory symptoms often spread rhinovirus. You can get a cold by touching a person with a cold (for example, by shaking hands) and then touching your nose or eyes, or by touching a surface that a person with a cold has touched, such as a telephone or keyboard. Colds are also transmitted through the air, when someone with a cold coughs or sneezes. Stress may increase your risk of catching a cold. Although you're more likely to get a cold in winter, exposure to cold, outdoor air does not increase your risk of getting sick.
People more likely to get colds include:
- Children, especially those who attend day care or whose parents smoke
- Smokers and those exposed to second hand smoke
- Those exposed to industrial smoke, toxic fumes, or other air pollutants
- People with immune system disorders, such as HIV, AIDS, or cancer, or who take medications that suppress the immune system, such as corticosteroids
- People under a fair amount of stress
Most people treat colds without seeing a doctor. If you do see a doctor, he or she will make a diagnosis based on your symptoms and exam. The doctor may take a throat culture to rule out strep throat. If you have an underlying lung condition, such as asthma or emphysema, you should let your doctor know right away when you get a cold.
Although anyone can get a cold, there are things you can do to boost your immunity and make you less susceptible.
- Wash your hands frequently.
- Exercise regularly.
- Eat a diet rich in fruits and vegetables, and low in fat.
- Get enough rest.
- Reduce stress and your reaction to stress. Yoga, tai chi, or other forms of relaxation may help.
With a cold, the goal of treatment is to improve your symptoms as quickly as possible. But even if you do nothing, they should go away within a week to 10 days. Antibiotics cannot treat your cold. However, there are medications, herbs, supplements, and homeopathic remedies that may make you feel better while you have a cold.
- Drink a lot of water to help loosen mucus.
- Drink hot beverages. Studies show that a hot drink provides immediate and lasting relief of cold symptoms such as runny nose, cough, sneezing, and sore throat.
- Rest to restore your energy and avoid complications, such as bronchitis or pneumonia.
- Eat a diet rich in fresh fruits and vegetables which provide lots of antioxidants -- substances that may help boost your immune system -- especially vitamins A and C.
- Use a cool-mist humidifier to ease nasal congestion and sore throat. Warm steam helps, too. Try sitting in the bathroom with the door closed and running a hot shower.
- Nasal irrigation -- using saline solution to flush out the nasal passages -- can help relieve cold symptoms.
A number of over-the-counter medications are available to help treat cold symptoms. You should not give children under the age of 6 any over-the-counter cold or cough medicine unless your pediatrician tells you to do so.
Decongestants -- help open your nasal passages so you can breathe easier. However, if decongestant nasal sprays or drops are used for more than 3 days, they can cause congestion to come back and get worse. Decongestants are often combined in cold medicines with antihistamines, cough suppressants, and pain relievers. People with heart disease, high blood pressure, diabetes, or glaucoma should not take decongestants. Popular brands of decongestants include Sudafed, Afrin, and Neo-Synephrine.
Antihistamines -- can temporarily relieve a runny nose by drying up nasal secretions. Non-drowsy antihistamines that are available over-the-counter include loratadine (Claritin), fexofenadine (Allegra), and cetirizine (Zyrtec).
Cough medicines -- cough suppressants (for a dry cough) or expectorants (for a wet, productive cough that brings up mucous) are available over the counter and by prescription.
Pain relievers -- such as aspirin, acetaminophen (Tylenol), and ibuprofen (Advil, Motrin) can be used for fever, body aches, and headaches. Children under the age of 19 should not take aspirin due to the risk of a rare but serious illness called Reye's syndrome.
Nutrition and Dietary Supplements
Because supplements may have side effects or interact with medications, you should take them only under the supervision of a knowledgeable health care provider. Be sure to talk to your doctor about any supplements you are taking or considering taking.
- Chicken soup -- Chicken soup and warm liquids such as broth or tea can help soothe a sore throat and loosen mucus, which in turn helps ease congestion from a cold.
- Honey -- Preliminary research suggests that giving honey to children at bedtime may help reduce cough and common cold symptoms. Honey is not recommended for children under 1 year because of the risk of exposure to C. botulinum spores.
- Probiotics (Lactobacillus) -- So-called "good" bacteria, or probiotics, help prevent infections in the intestines. And there is preliminary evidence that they might help prevent colds, too. One study found that children in daycare centers who drank milk fortified with Lactobacillus had fewer and less severe colds. Another study of children in daycare found those who took a specific combination of Lactobacillus and Bifidobacterium had fewer flu-like symptoms. Several studies that examined probiotics combined with vitamins and minerals also found a reduction in the number of colds caught by adults. But it's not possible to say whether the vitamins, minerals, probiotics, or a combination of the three were responsible for the fewer colds. People with weakened immune systems, or who take drugs to suppress the immune system, should not take probiotics except under a doctor's supervision.
- Vitamin C -- Despite the popular belief that vitamin C can cure the common cold, scientific evidence is lacking. Scientists have found only a small reduction in the duration of a cold (about 1 day) when people take vitamin C supplements regularly -- not just at the beginning of a cold. The only other piece of evidence supporting vitamin C for preventing colds comes from studies looking at people who exercise in extreme environments -- athletes such as skiers and marathon runners, and soldiers in the Arctic. In these studies, vitamin C seemed to reduce the risk of getting a cold. Talk to your doctor about any pros and cons with using vitamin C during cold and flu season. Some people believe that you have to take very high doses of vitamin C to get any benefit. But you should only use such high doses under your doctor's supervision.
- Zinc -- Your body needs zinc for its immune system to function properly. So some people think that zinc helps protect against catching a cold. But the evidence has been decidedly mixed, with some studies finding a benefit from zinc lozenges and others showing no effect. A review of studies that compared zinc to placebo found that most of them had flaws that made any positive results unreliable. Other studies suggest that zinc nasal sprays reduce nasal stuffiness. But these sprays have been reported to cause permanent loss of smell and are not recommended. If you do decide to try zinc lozenges for a cold, remember that getting too much zinc (more than 50 mg per day over a long period of time) can be dangerous. People taking cisplatin, penicillamine, and quinolone or tetracycline antibiotics should not take zinc.
The use of herbs is a time-honored approach to strengthening the body and treating disease. However, herbs can trigger side effects and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care practitioner. Before giving any herbs to a child to treat a cold, talk to your pediatrician.
Echinacea (Echinacea purpurea, 300 mg, 3 times per day) -- Although evidence on whether echinacea works to prevent or treat colds has gone back and forth, recent evidence is encouraging. An analysis of 14 scientific studies found that people who took echinacea reduced their risk of getting a cold by 58 percent, and reduced the duration of a cold by an average of a day and a half. However, many of the studies used echinacea in combination with another herb or vitamin. Therefore, it's impossible to say that echinacea was responsible for the benefit. Plus, there's significant variation in echinacea products. So use caution before taking a supplement. Women who are pregnant or breastfeeding, people who have autoimmune diseases, or people taking drugs that suppress the immune system (such as corticosteroids or methotrexate) should not take echinacea without asking their doctors first. People who are allergic to ragweed should ask their doctors before taking echinacea.
In addition to echinacea, several other herbs that are used to strengthen the immune system may also be beneficial in preventing you from catching a cold. As is true with echinacea, these herbs should not be taken by anyone taking drugs to suppress their immune system.
- Andrographis (Andrographis paniculata) -- One study found that andrographis, an herb used in Ayurvedic medicine, combined with eleuthero or Siberian ginseng (Eleutherococcus senticosus) in a formula called Kan Jang, helped reduce cold symptoms. Pregnant or breastfeeding women should not take andrographis. People who have diabetes, autoimmune disease, or those who take blood thinners or blood pressure medications should not take andrographis without first asking their doctor. Men or women who have fertility concerns may wish to talk to their doctor before taking andrographis due to some concern that it may interfere with fertility.
- Garlic (Allium sativum) -- In one study, people who took garlic for 12 weeks between November and February had 63% fewer colds than people who took placebo. Those who did get a cold recovered about 1 day faster. Because garlic can increase the risk of bleeding, people who take blood thinners, such as aspirin or warfarin (Coumadin), should not take garlic. Women who are pregnant or breastfeeding should talk to their doctors before taking garlic supplements. Garlic can interfere with several medications, including some drugs used to treat HIV/AIDS. If you take prescription medication, speak with your doctor before taking garlic supplements.
- Ginseng (Panax quinquefolius, 400 mg per day) -- At least 2 studies suggest that taking American ginseng may help prevent colds, as well as reduce the number of colds and the severity of symptoms. Ginseng interacts with a number of medications. So ask your doctor before taking it. Ginseng may not be appropriate for people who have certain illnesses or underlying conditions, including but not limited to, bleeding disorders, mental illness, hormone-sensitive cancers, and insomnia. Pregnant or breastfeeding women should not take ginseng.
- Elder or elderberry (Sambucus nigra) -- Elder may help reduce the symptoms of colds and flu by lessening congestion and possibly helping you sweat. One study suggested that using a standardized elderberry extract, Sambucol, could shorten the duration of flu by about 3 days. Sambucol also contains other herbs plus vitamin C. So it isn't known whether elder by itself would have the same effect. Pregnant and breastfeeding women should not take elder. People with diabetes or high blood pressure, autoimmune disease, or those who take blood thinners such as aspirin or warfarin (Coumadin) should ask their doctor before taking elder.
- Eucalyptus (Eucalyptus globulus) -- Eucalyptus is used in many remedies to treat cold symptoms, particularly cough. It can be found in many lozenges, cough syrups, and vapor baths throughout the United States and Europe. Fresh leaves can be used in teas and gargles to soothe sore throats. Ointments containing eucalyptus leaves are also applied to the nose and chest to relieve congestion and loosen phlegm. Do not take eucalyptus oil by mouth because it can be poisonous.
- Goldenseal (Hydrastis canadensis) -- Goldenseal is often combined with echinacea in herbal cold remedies, although scientific evidence that it works is lacking. Women who are pregnant or breastfeeding should talk to their doctor before taking goldenseal. Goldenseal interacts with a number of medications and should not be taken by people with certain medical conditions. So ask your doctor before taking it.
- Licorice (Glycyrrhiza glabra) -- Licorice root is a traditional treatment for sore throat, although scientific evidence is lacking. Licorice interacts with a number of medications, so ask your doctor before taking it. People with high blood pressure, kidney disease, liver disease, hypokalemia, a history of hormone sensitive cancers and/or illnesses, or heart disease, women who are pregnant or breastfeeding, and those who take blood thinners, such as aspirin or warfarin (Coumadin) should not take licorice. You should not use licorice for extended periods of time, unless specifically directed to do so by your doctor.
- Marshmallow (Althea officinalis) -- Although there isn't any scientific evidence that it works, marshmallow has been used traditionally to treat sore throat and cough.
- Peppermint (Mentha x piperita) -- Like eucalyptus, peppermint is widely used to treat cold symptoms. Its main active agent, menthol, is a good decongestant. Menthol also thins mucus and works as an expectorant, meaning that it helps loosen and break up phlegm. It is soothing and calming for sore throats and dry coughs as well. Don't use peppermint or menthol with infants. Do not take peppermint oil by mouth.
- Slippery elm (Ulmus fulva) -- Slippery elm may help ease a sore throat and has been used traditionally for this purpose, although scientific evidence is lacking. Slippery elm may affect how your body absorbs some medications, so wait at least 1 hour after taking any other medications before taking slippery elm. Pregnant or breastfeeding women should avoid slippery elm. Some herbalists caution against the use of slippery elm during pregnancy, saying it can increase the risk of miscarriage. Others dispute this claim.
Although few studies have examined the effectiveness of specific homeopathic therapies, professional homeopaths may consider the following remedies for the treatment of the common cold based on their knowledge and experience. However, it is important to note that cold symptoms are viewed in homeopathic medicine as the body's natural way of eliminating a virus. For this reason, homeopathic doctors may recommend no treatment at all. If a remedy is selected, usually it is intended to boost the body's natural immune response. Before prescribing a remedy, homeopaths take into account a person's constitutional type. A constitutional type is defined as a person's physical, emotional, and psychological makeup. An experienced homeopath assesses all of these factors when determining the most appropriate treatment for each individual.
- Aconitum -- for symptoms including fever, anxiety, and thirst, that start abruptly, often following exposure to a cold climate or draft; most effective during the first 24 hours of the illness
- Allium cepa -- for colds with clear watery discharge that burns and/or irritates the nostrils; red, burning eyes; and symptoms that worsen in warm rooms and in the evening
- Arsenicum album -- for colds with watery, burning discharge from the eyes and nose, throbbing headache, nasal congestion that is not relieved by sneezing, dry mouth, sensitivity to cold, and a thirst for small sips of fluid
- Belladonna -- for colds with sudden onset of high fever, flushed face, watery nasal discharge, sore throat, throbbing headache, earache, and cough that tends to worsen at night; this remedy is most appropriate for individuals who are often agitated and sometimes delirious; these symptoms may cause children to cry
- Bryonia -- for chest colds with spastic cough that produces only a small amount of mucus and sharp chest pain that worsens with inhalation and while coughing; a dull headache, little to no nasal discharge, and sneezing may also be present
- Euphrasia -- for colds with excessive, non-irritating watery discharge that tends to worsen in the morning and when the person is lying down
- Ferrum phosphoricum -- for the early stages of a cold with slight fever, flushed face (redness may be patchy), and fatigue; may also be used in children with nosebleeds or bloody nasal discharge
- Gelsemium -- for colds that have gradual onset with watery nasal discharge that causes irritation, a feeling of fullness, or tickling in the nose and/or the back of the throat, muscle aches, fatigue, lack of energy, lightheadedness, and a headache with pain in the back of the head
- Hepar sulphuricum -- for late stages of a cold when nasal discharge turns from watery to thick, yellow, and foul smelling; symptoms tend to worsen in the evening and with cold and wind
- Mercurius -- for fluctuating body temperature and thick, yellow nasal discharge with a foul odor; symptoms may also include bad breath and a swollen tongue
- Pulsatilla -- for coughs and nasal congestion with thick, yellow-green mucus that does not burn the skin; symptoms tend to worsen in warm, stuffy rooms and when the person is lying on his or her back; this remedy is most appropriate for children (even newborns) and adults who are weepy, have mood swings, and are easily influenced by others
A study of a small number of university students suggests that practicing relaxation techniques on a regular basis may help reduce the duration of a cold or the flu. A similar study of children reached the same conclusion. Some good stress reduction techniques include meditation, deep relaxation, yoga, tai chi, and breathing exercises.
Tell your health care provider if you are pregnant or think you might be pregnant. Some medications, herbs, and supplements may be harmful to your baby and should not be taken if you are pregnant or trying to become pregnant.
If you have asthma, emphysema, or any other respiratory disease, you should talk to your doctor as soon as you develop cold symptoms.
Warnings and Precautions
If your symptoms aren't better in 7 to 10 days, you should call your doctor. Other reasons to see your doctor include high fever (above 102° Fahrenheit), thick, green nasal discharge, or development of a productive cough (cough with phlegm), especially if it is thick and green as well.
Prognosis and Complications
Colds usually get better within 7 to 10 days. Some potential complications include:
- Worsening of a pre-existing respiratory condition, such as asthma or emphysema
- Ear infection
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Cold; Respiratory infection - cold