We get colds because viruses infect the lining of our nose and throat, and our immune system’s reaction to those viruses produces the familiar symptoms.

What a cold actually is

A “common cold” is an infection of the upper airways (nose, sinuses, throat, sometimes the upper windpipe).

More than 200 different respiratory viruses can cause it, but rhinoviruses are the most frequent culprits.

Because there are so many different viruses and subtypes, you can catch colds again and again throughout your life.

When a cold virus lands on your nose, throat, or eye surface and gets inside cells, it starts making copies of itself.

Your immune system responds by sending white blood cells and inflammatory chemicals, which cause congestion, runny nose, sore throat, and that “blah” feeling.

How the virus spreads

Viruses that cause colds spread very efficiently in everyday life.

Main routes:

  • Breathing in droplets when someone coughs, sneezes, or talks near you.
  • Shaking hands or close contact with someone who has a cold.
  • Touching contaminated objects (doorknobs, phones, keyboards, toys, dishes, towels) and then rubbing your eyes, nose, or mouth.

Once the virus reaches your mucous membranes (moist linings of nose, mouth, eyes), infection can begin.

Why colds are worse in winter

People often think “I was outside in the cold rain, so I caught a cold,” but the story is more about viruses and behavior than temperature alone.

Several factors stack up in colder months:

  • More time indoors: People crowd into homes, schools, offices, buses, and planes, so viruses spread more easily in shared air and on surfaces.
  • Nasal changes: Colder, drier air can dry out or cool the nasal lining, which may slightly weaken local immune defenses and make it easier for viruses to take hold.
  • Viral survival: Some cold viruses survive longer in cool, dry conditions, increasing the chance they stay infectious long enough to reach another person.
  • Seasonal patterns: Many cold-causing viruses naturally peak in fall and winter in both children and adults.

So you don’t get sick from “cold air” itself, but the winter environment and behaviors help viruses win.

Why some people seem to get more colds

Not everyone’s risk is the same; a mix of environment, immune strength, and lifestyle makes a big difference.

Key reasons:

  • Age: Young children in daycare or school get many more colds because their immune systems are still building experience and they’re constantly exposed to new viruses.
  • Weakened immunity: Long-term illnesses, immune disorders, certain medications, pregnancy, and older age can all reduce defenses.
  • Environment and exposure: Living or working in crowded spaces, frequent travel, having family members who bring infections home, or exposure to secondhand smoke all raise your odds.
  • Lifestyle factors: Poor sleep, high stress, poor diet, and hygiene lapses (like infrequent handwashing or sharing utensils) can make colds more likely.
  • Genetics: Early research suggests some people’s genetic make-up may make their immune responses more or less effective against cold viruses.

An everyday example: a stressed, sleep-deprived parent with young kids in daycare will usually catch colds more often than a well-rested remote worker who lives alone.

Can we avoid or “cure” colds?

There is no complete cure or universal vaccine for the common cold because so many different viruses cause it.

Treatment focuses on easing symptoms (fluids, rest, pain relievers, saline sprays, sometimes decongestants) while your immune system clears the infection.

You can lower your chances of catching colds by:

  • Washing hands frequently with soap and water.
  • Avoiding touching your face (especially eyes, nose, mouth) when out and about.
  • Keeping distance from people who are clearly sick when possible.
  • Not sharing utensils, cups, or towels with someone who has a cold.
  • Getting good sleep, managing stress, not smoking, and eating a balanced diet to support immune function.

From an evolutionary standpoint, colds “succeed” because they spread easily, usually cause mild illness, and don’t often kill or completely disable the host—so viruses keep circulating in the population year after year.

Information gathered from public forums or data available on the internet and portrayed here.