How Long Are You Contagious With a Cold?

If you have a cold, you're usually the most contagious during the first four days of symptoms. However, some viral strains can continue to spread for up to a month.

Each year, millions of cases of the common cold occur in the United States. According to the Centers for Disease Control and Prevention (CDC), hundreds of different cold viruses spread easily from person to person.

The common cold is an almost inevitable part of life and can be difficult to avoid. Understanding the risk of transmission and taking proper precautions can help stem the spread of colds.

This article explains how colds are spread and when they are the most contagious. It also discusses ways to lower your odds of catching a cold and how to prevent spreading a cold to a loved one.

How Long Are You 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. For the common cold, symptoms start to develop one to three days after exposure to the virus.

Colds are most contagious one to four days after symptoms develop. Common cold symptoms include:

• Congestion
• Coughing
• Headache
• Runny nose
• 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. Cold viruses can persist in the body for up to four weeks.

While the risk of transmission decreases rapidly over time, infecting others may still be possible even if you no longer have symptoms.

How Do Colds Spread?

Cold viruses are spread through airborne droplets, person-to-person contact, and contact with contaminated surfaces.

When a person is sick with a respiratory virus, coughing and sneezing propel droplets into the air. The virus-loaded droplets 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.

Most colds are caused by strains in the rhinovirus and coronavirus families. Adenovirus, metapneumovirus, parainfluenza, and respiratory syncytial virus (RSV) are other viruses that cause upper respiratory symptoms.

How Long Are You Contagious After a Cold?

One reason colds spread so fast is that you become contagious before you probably realize it. In fact, most people become contagious with a cold for one to two days before their symptoms start.

Once symptoms set in, you are considered contagious for as long as your symptoms are present, lasting anywhere from five days to two weeks after your symptoms start.

How to Prevent Spreading or Catching a Cold

Unfortunately, colds just happen sometimes. You can catch a cold anywhere other people are, even if you practice great hygiene and try your best to avoid close contact with someone who is sick.

With that being said, there are steps you can take to lower your chances of catching a cold. And, if you do get happen to catch a cold, there are several ways you can help stop it from spreading.

Reduce Your Chances of Spreading a Cold

If you get a cold, the best way to avoid spreading the virus is to isolate yourself. When around others, it 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. 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 when you are in contact with people who are at an increased risk of complications. These include:

• Infants or toddlers
• Older adults
• Persons with asthma
• 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. To be safe around high-risk people, continue to use precautions for a week after cold symptoms abate.

Reduce Your Chances of Catching a Cold

You can reduce your chances of catching a cold by making a habit of the following:

Wash your hands: As a general rule, try to wash your hands at least 10 times per day using soap and water or an alcohol-based hand sanitizer. Always wash your hands before making food and after taking care of someone else who is sick.

Avoid touching your face: Viruses that cause colds can enter your body through your eyes, nose, and mouth. Take care to avoid touching your face unless it is necessary; if you must touch your face, wash your hands first.

Stay away from people who are sick: If you live with someone who is sick, try to spend your time in separate rooms and never share food, drinks, or linens (e.g., sheets and towels). If your child is sick, wash any toys they use thoroughly.

Eat a healthy diet: You can help keep your immune system strong by eating a healthy, colorful, and balanced diet. Enrich your diet with plenty of fruits, vegetables, and probiotics (e.g., kimchi, sugar-free yogurt, and kombucha). Also, drink lots of water to help flush toxins from your system. Avoid eating too much sugar, which can weaken your immune system when consumed in excess.

If you smoke cigarettes, quit: Smoking weakens the immune system, making it easier to catch a cold-causing virus and harder to fight one off.

How to Manage Cold Symptoms

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
  

When to See a Healthcare Provider for a Cold

See your healthcare provider if you experience any of the following:

• Fever that comes and goes, that worsens or does not get better despite taking fever-reducing medicine, or that is 103°F or higher
• Shortness of breath or difficulty breathing
• A cough that brings up bloody mucus
• Symptoms that persist for more than three weeks, even if they are not severe
• Pain or pressure in your chest
• Dizziness or lightheadedness, confusion, or loss of coordination
• Severe headache or extreme sensitivity to light

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.