Health Library

What Is a Cold?

The common cold is a contagious viral infection of the upper respiratory tract.

Most adults catch a cold from time to time, but kids can get 8 colds per year or more. They’re the top reason kids visit the doctor and miss school.

What Causes a Cold?

Most colds are caused by viruses — known as

rhinoviruses
— carried in invisible droplets in the air or on things we touch. These viruses can get into the protective lining of the nose and throat, setting off an immune system reaction that can cause a sore throat, headache, and trouble breathing through the nose.

Dry air — indoors or outside — can lower resistance to infection by the viruses that cause colds. So can being a smoker or being around someone who smokes. Smokers are more likely to catch a cold than people who don’t smoke, and their symptoms probably will be worse and last longer, and can even lead to bronchitis or pneumonia.

Not wearing a jacket or sweater when it’s chilly, sitting or sleeping in a draft, and going outside while your hair’s wet do not cause colds.

What Are the Signs & Symptoms of a Cold?

The first symptoms of a cold are often a tickle in the throat, a runny or stuffy nose, and sneezing. Kids with colds also might feel very tired and have a sore throat, cough, headache, mild fever, muscle aches, and loss of appetite. Mucus from the nose may become thick yellow or green.

Are Colds Contagious?

Colds are the most common infectious disease in the United States. They’re very contagious, especially in the first 2–4 days after symptoms start. They can even spread for a couple of weeks after someone starts feeling sick.

Colds spread through person-to-person contact or by breathing in virus particles, which can travel up to 12 feet through the air when someone with a cold coughs or sneezes. Touching the mouth or nose after touching a contaminated surface can also spread a cold.

How Long Do Colds Last?

Cold symptoms usually begin 2 or 3 days after exposure to a source of infection. Most colds clear up within 1 week, but some last a bit longer.

How Are Colds Diagnosed?

Your doctor won’t be able to find which virus caused the illness, but can check your child’s throat and ears and take a throat culture to make sure the symptoms aren’t from another condition that may need treatment. If symptoms get worse instead of better after 3 days or so, the problem could be strep throat, sinusitis, pneumonia, or bronchitis, especially if your child smokes.

If symptoms last for more than a week; appear at the same time every year; or happen when your child is around pollen, dust, or animals, an allergy could be to blame. Kids who have trouble breathing or wheeze when they catch a cold could have asthma.

How Are Colds Treated?

Colds will clear up on their own without specific medical treatment. Medicine can’t cure a cold, but can ease symptoms like muscle aches, headache, and fever. You can give your child acetaminophen or ibuprofen based on the package directions for age or weight.

Never give aspirin to children or teens, as such use has been linked to Reye syndrome, a rare but serious condition that can be fatal.

Many experts now believe that there’s usually no reason to give over-the-counter (OTC) decongestants and antihistamines to any child younger than 6. There’s little proof that these medicines work, and decongestants can cause hallucinations, irritability, and irregular heartbeats, especially in infants.

Can Colds Be Prevented?

Because so many viruses cause colds, there isn’t a vaccine to protect against them. To help avoid catching one, kids should:

• steer clear of anyone who has a cold
• avoid secondhand smoke
• wash their hands well and often, especially after blowing their noses
• sneeze or cough into a tissue or their elbow, not into their hands
• not share towels, drinking glasses, or eating utensils with someone who has a cold
• not pick up other people’s used tissues

Experts aren’t sure whether taking extra zinc or vitamin C can limit how long cold symptoms last or how severe they get, but large doses taken every day can cause negative side effects. Studies on herbal remedies, like echinacea, are either negative or aren’t conclusive. Few good scientific studies of these treatments have been done in kids.

Talk to your doctor before you give your child any herbal remedy or more than the recommended daily allowance (RDA) of any vitamin or supplement.

How Can Parents Help?

To help ease cold discomfort, you can:

• Put saline (saltwater) drops in the nostrils to relieve nasal congestion.
• Rn a cool-mist humidifier to increase air moisture.
• Dab petroleum jelly on the skin under the nose to soothe rawness.
• Give hard candy or cough drops to relieve sore throat (only for kids older than 6).
• Run a warm bath or use a heating pad to soothe aches and pains.
• Run a hot shower to create a steam-filled bathroom where your child can sit to help clear stuffiness.

What about chicken soup? There’s no real proof that eating it can cure a cold, but sick people have been swearing by it for more than 800 years. Chicken soup contains a mucus-thinning amino acid called cysteine, and some research shows that chicken soup helps control congestion-causing white cells, called neutrophils.

The best plan, though, is not to worry about whether to "feed a cold" or "starve a fever." Just make sure your child eats when hungry and drinks plenty of liquids like water or juice to help replace the fluids lost during a fever or from mucus production.

When Should I Call the Doctor?

Always call the doctor if you think your child might have more than a cold, your child gets worse instead of better, or if your child:

• coughs up a lot of mucus
• is short of breath
• is unusually tired
• can’t keep food or liquids down or has trouble drinking
• has a headache that gets worse
• has facial or throat pain that gets worse
• has a severely painful sore throat that makes it hard to swallow
• has fever of 103°F (39.3°C) or higher, or a fever of 101°F (38.0°C) or higher that lasts for more than a day
• has chest or stomach pain
• has swollen glands (lymph nodes) in the neck
• has an earache

Like most viral infections, colds just have to run their course. Getting plenty of rest and drinking lots of fluids — juice and water — can help your child feel better while on the mend.

Keeping up regular activities like going to school probably won’t make a cold any worse. But it will make it more likely to spread to classmates or friends. So you might want to put some daily routines aside until your child feels better.