What is a cold?

A cold is a contagious upper respiratory infection that affects your nose, throat, sinuses and trachea (windpipe). More than 200 different viruses can cause a cold, but most colds are caused by a rhinovirus.

How common are colds?

As its name implies, the common cold is widespread. You’ll probably have more colds in your lifetime than any other illness. Adults catch two to three colds a year, while young children come down with a cold four or more times a year.

Are colds contagious?

Colds spread from person to person. For you to become infected, the virus has to get to one of your mucous membranes — the moist lining of the nostrils, eyes or mouth. That happens when you touch a surface or breathe moist air that contains the cold virus.

For example, when a sick person sneezes or coughs, droplets of fluid containing the cold virus are launched into the air. If you breathe in those droplets, the cold virus takes root in your nose. You can also leave virus particles on surfaces you touch when you’re sick. If someone else touches those surfaces and then touches their nostrils, eyes or mouth, the virus can get in.

Why do colds occur in the winter?

You can catch a cold any time of year, but it’s more likely during colder months. In winter, people stay indoors and are in closer contact with each other.

A recent study in mice suggests cold temperatures may also affect your immune system’s response. Researchers found that when cooler air lowered nose temperature, mouse immune systems had a harder time stopping the rhinovirus from multiplying. The same may be true in humans.

Why do children get more colds?

Because young children haven’t been exposed to viruses before, they get more colds than adults. Their immune systems have to learn how to recognize and deal with these new germs. By the time you become an adult, you’ve had many colds. It’s easier for your immune system to identify and attack similar viruses.

Children are also in close contact with other children. Kids typically don’t cover their coughs and sneezes or wash their hands before touching their faces — steps that prevent the virus from spreading.

What causes the common cold?

Rhinoviruses cause up to 50% of common colds. There are more than 100 different rhinoviruses. But other types of viruses can also cause cold symptoms.

What are the symptoms of a cold?

Within one to three days of picking up a cold virus, you’ll get symptoms like:

How can you tell the difference between a cold and flu?

It can be hard to tell whether you have a cold or flu, since many of the symptoms are the same. Both are widespread during the colder months and affect the upper respiratory system (nose, throat and trachea). But different viruses cause cold and flu. The flu comes from the influenza virus, while many other types of viruses cause colds.

The main difference between cold and flu is that you’re more likely to have a fever and chills with flu. Adults don’t usually get a fever with a common cold, although kids sometimes do.

The flu also causes body aches and more severe symptoms than a cold. Although both the cold and flu can lead to complications, flu complications can be life-threatening.

What’s the difference between a cold and COVID-19 (the novel coronavirus)?

You might have heard that the common cold is a coronavirus. Coronaviruses are a group of viruses that can cause upper respiratory infections. While rhinoviruses cause most types of common cold, a few are caused by different coronaviruses. Most people recover quickly from these common colds.

Coronaviruses may also travel into the lungs and lead to pneumonia and other complications that can be fatal. A new (novel) type of coronavirus, discovered in late 2019, causes a specific disease known as COVID-19. Early symptoms that make COVID-19 different from the common cold include:

  • Fever.
  • Chills and shaking.
  • Shortness of breath.
  • Loss of taste or smell (anosmia).
  • Diarrhea.

What’s the difference between the common cold and a chest cold?

A chest cold, or acute (short-term) bronchitis, causes irritation and a buildup of mucus (snot) in the lungs. Common colds turn into chest colds when the virus travels from the nose and throat to the lungs. Occasionally, bacteria cause chest colds.

You can have a cough with a common cold or a chest cold. But chest colds produce a wet cough, meaning you may feel or cough up phlegm. You may also have:

  • A cough that keeps you up all night.
  • Shortness of breath.
  • A sore chest.

Does having a cold affect pregnancy?

Having a cold during pregnancy isn’t usually dangerous. But you do need to be careful with what cold medications you take to treat symptoms. Your healthcare provider can let you know which ones are safe to use during pregnancy.

If you think you may have flu, or if you develop a fever, you should contact your healthcare provider right away. You may need immediate treatment. Fever during early pregnancy is associated with birth defects.

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