Cold: The Basics

Common Cold: The Basics

Sneezing, scratchy throat, runny nose -- everyone knows the first miserable
signs of a common cold. But what is a common cold really? What causes you
to catch colds frequently while your best friend stays well? And -- more
importantly -- how can you prevent getting a common cold this season? Here are
some common cold basics to help you protect yourself and your family from
getting sick.

What Is a Common Cold?

The common cold is a group of symptoms in the upper respiratory tract caused
by a large number of different viruses. Although more than 200 viruses can cause
the common cold, the perpetrator is usually the rhinovirus, which is to blame
for causing 10% to 40% of colds. Also, the coronaviruses cause about 20% of
colds and the respiratory syncytial virus (RSV) causes 10% of colds.

The rhinovirus (or other cold virus) enters your body through your nose or
mouth and is easily spread when you touch someone or touch common objects (the
computer keyboard or mouse, the telephone receiver, a doorknob, or eating
utensils). If you aren’t cautious about hand washing, you can
spread the common cold to family, friends, coworkers, and people you’ve never
met at a restaurant or the supermarket.

What Causes a Common Cold?

While getting chilled or wet is not a common cold cause,
there are factors that make you more susceptible to catching a cold virus. For
example, you are more likely to catch a common cold if you are excessively
fatigued, have emotional distress, or have allergies with nose and
throat symptoms.

For more detail, see WebMD’s Common Cold Causes.

How a Common Cold Starts

With a common cold, you catch the virus from another person who is infected
with the virus. This usually happens by touching surface contaminated with cold
germs, and then touching your nose or mouth. You can also catch a cold by
encountering secretions someone has sneezed into the air.

A cold begins when a cold virus attaches to the lining of your nose or
throat. Your immune system sends white blood cells out to attack this germ.
Unless you've encountered that exact strain of the virus before, the initial
attack fails and your body sends in reinforcements. Your nose and throat get
inflamed and produce a lot of mucus. With so much of your body’s energy
directed at fighting the cold virus, you’re left feeling tired and
miserable.

Although the common cold is usually mild, it is a leading cause of doctor
visits and missed days from school and work. According to the CDC, 22 million
school days are lost annually in the U.S. because of the common cold. Some
estimates state that Americans suffer 1 billion colds annually.

Common Cold Symptoms

With the common cold, you may have cold symptoms such as
an itching or sore throat with sneezing, nasal congestion, watery eyes, and
mucus drainage. More severe symptoms, such as high fever or muscle aches, may
indicate you may have the flu and not a cold.

For more detail, see WebMD’s Common Cold Symptoms: What
You Might Feel

Kids and Common Colds

Children have about 5 to 7 colds per year. A key reason why colds are so
common in children is because kids spend time at school or in daycare centers
where they are in close contact with other kids most of the day. Another reason
is kids have not developed as strong an immune system against colds. In families
with children in school, the number of colds per child can be as high as 12
annually. Adults average about 2 or 3 colds a year, although the range varies
widely. Women, especially those aged 20 to 30 years, have more colds than men,
possibly because of their closer contact with children. On average, people older
than 60 have less than one cold a year.

For more detail, see WebMD’s Kids and Colds: Germs in
the School Room.

Preparing for Cold Season

In the United States, most colds occur during the fall and winter. Beginning
in late August or early September, the rate of colds increases slowly for a few
weeks and remains high until March or April, when it declines. The seasonal
variation may relate to the opening of schools and to cold weather, which prompt
people to spend more time indoors and increase the chances that viruses will
spread.

Seasonal changes in relative humidity also may affect the prevalence of
colds. The most common cold-causing viruses survive better when humidity is
low—the colder months of the year. Cold weather also may make the inside lining
of your nose drier and more vulnerable to viral infection.

When to Call the Doctor

Remember, common colds are viral—not bacterial. Yet many people
still ask their doctors for antibiotics when they experience common cold misery.
Antibiotics kill
bacteria -- not viruses. Antibiotics cannot help a viral infection
like a cold.

While most colds last around 7 to 10 days, if your symptoms continue, you may
need to call the doctor.
Sometimes common colds can lead to bacterial infections in your lungs, sinuses,
or ears that require medical treatment such as antibiotics.