How Long Is a Cold Contagious?

Millions of cases of the common cold occur in the United States each year, spreading easily from person to person. Colds can be caused by hundreds of different viruses, making it impossible to develop a single vaccine or medication able to prevent or treat it.

For this reason alone, colds are an almost inevitable part of life and sometimes difficult to avoid. With that said, you can reduce the risk of transmission by isolating the infected person until they are no longer contagious.

This article explains how colds are spread and when they are the most contagious. It also describes ways to prevent transmission of the virus if you or someone you care for gets a cold.

How Colds Spread

Colds are spread through airborne droplets, person-to-person contact, and contact with contaminated surfaces. When you are sick, coughing and sneezing can propel droplets into the air where they can land on surfaces or enter someone else's upper respiratory tract.

Cold viruses can live on surfaces for several hours, making it possible to become infected if you touch a contaminated surface and then your nose. This is referred to as fomite transmission.

How Long You're Contagious

The incubation period for a cold virus is 24 to 72 hours. This is how long it takes for symptoms to appear after you become infected. With respect to the common cold, this means you will start to develop symptoms one to three days after exposure to the virus.

Colds are most contagious one to four days after symptoms develop. These may include a runny nose, congestion, coughing, headache, and sore throat. Not everyone gets all these symptoms, and the severity can vary.

Most colds last for about a week, but it's possible to spread the virus after that. In fact, cold viruses can persist in the body for up to three weeks. While the risk of airborne or fomite transmission decreases rapidly over time, it may still be possible to infect others even if you no longer have symptoms.

Prevention Tips

If you get a cold, the best way to avoid spreading the virus is by isolating yourself. It also helps to wear a face mask to catch respiratory droplets if you cough or sneeze. People who live with you can do the same.

Be sure to cover your mouth when coughing or sneezing. It is best to cough or sneeze into the crook of your arm; in this way, you can avoid contaminating your hand. You can cough or sneeze into a tissue but will need to wash your hands afterward (or use an alcohol-based hand sanitizer).

You and others in your household should frequently wash your hands and regularly clean surfaces. Try your best to avoid touching your face (like scratching or rubbing your nose).

It's especially important to take these precautions if you live with older adults, infants or toddlers, persons with asthma, or people with weakened immune systems. While a cold may not necessarily be worse in these individuals, your symptoms may turn out to be something more dangerous, like the flu or COVID-19.

If You Are Exposed

While there are no vaccines to prevent colds or surefire ways to avoid cold symptoms, there are things you can do that may reduce the severity or duration of a cold. These include:

• Getting plenty of rest
• Increasing fluid intake to prevent dehydration
• Sipping warm tea, warm soup, or warm apple juice to loosen congestion
• Using a cool-mist vaporizer or humidifier
• Gargling with salt water to relieve a sore throat
• Using over-the-counter saline nasal drops or sprays to treat a stuffy nose
  

Summary

Colds are spread by airborne droplets, person-to-person contact, and touching contaminated surfaces. Colds are most contagious one to four days after cold symptoms appear but may be contagious even longer.

If you get a cold, you can prevent the spread of the virus by isolating yourself, wearing a face mask, covering your mouth when coughing or sneezing, washing your hands frequently, and regularly cleaning surfaces.

Treating a cold properly, including getting plenty of rest, may reduce its duration or severity.

A Word From Verywell

No one enjoys catching a cold, but, by taking a few standard precautions, you may be able to avoid spreading the virus to others. Out of courtesy to others, it is best to take time off from work or school if you have cold symptoms.

The same applies if you are scheduled to go to an event or location where there will be a lot of people, such as a concert or a movie theater. Even if you're not entirely sure you are sick, you should avoid going out as you may inadvertently be the cause of a super-spreader event.