How Long Am I Contagious

This viral illness is also known as the kissing disease because that’s one of the ways you can pass it on to others. You might be contagious from the moment you’re infected, and that isn’t good because it often takes 4-7 weeks before you notice any of its flu-like symptoms. You can spread the disease the entire time you have it. Even once you feel better, you may be able to pass on the virus for as long as 18 months.

How Long Is a Cold Contagious?

The common cold is a viral infection that affects your upper respiratory tract. It’s a contagious disease, meaning that it can be spread from person to person.

You can transmit a cold to others a few days before your symptoms start, so you can possibly spread it to other people without even knowing it. Your infection continues to be contagious as long as you have symptoms.

The incubation period for the common cold is typically between 1 and 3 days. This is the time period between exposure to the virus and when you begin to notice symptoms. Once you develop symptoms, recovery from an uncomplicated cold usually takes about 7 to 10 days.

Since your infection is contagious from before your symptoms start until they improve, you can potentially pass the virus to others for up to 2 weeks.

This article will go into more detail about the common cold, how it’s spread, and what you can do to find relief.

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The viruses responsible for the common cold can enter your body through your nose, mouth, or eyes.

Cold viruses can spread through the air. When someone with a cold coughs, sneezes, talks, or laughs, they can spread respiratory droplets through the air that contain the cold virus. If you inhale these respiratory particles, you can get a cold.

You might also get a cold virus through direct contact. For example, someone with a cold may have the virus on their hands. If you shake hands with them and then touch your nose, mouth, or eyes afterward, you may develop a cold.

Contaminated objects and surfaces can also transmit the virus. Commonly contaminated objects include door handles, shared eating utensils, and shared toys.

According to recent research, the common cold virus can survive outside the body for 2 to 3 hours.

Colds tend to come on gradually. You may begin to notice symptoms between 1 to 3 days after exposure to the virus.

The most common cold symptoms typically include:

a tickle, soreness, or scratchiness in the back of your throat
a runny nose
nasal congestion
sneezing
a cough
mild body aches and pains
headache
not feeling well (malaise)
fever, although this is less common in adults

Some of these symptoms may develop earlier than others, while some symptoms like a cough, for instance, may last longer than a sore throat or a runny nose.

There’s no cure for the common cold. Instead, treatment revolves around relieving your symptoms. Self-care measures you can take at home to help ease your cold symptoms include:

drinking plenty of fluids
getting plenty of rest
using over-the-counter (OTC) medications to relieve symptoms like a sore throat, fever, and runny or stuffy nose

Some remedies claim to shorten the duration of a cold when taken as soon as you start noticing symptoms.

Here’s a look at some of the most popular cold remedies.

Oral zinc

Research suggests that taking zinc by mouth may reduce the length of a cold when taken within 24 hours after you first notice symptoms.

A 2017 meta-analysis examined seven clinical trials that included a total of 575 participants with a cold. It found that, on average, taking zinc reduced the duration of a cold by 33 percent.

A variety of dosages were examined during the clinical trials. However, there was no evidence that zinc doses over 100 milligrams per day were more effective than lower doses.

Taking oral zinc can have side effects, such as nausea and other digestive symptoms. It can also interact with some types of medication. Because of this, it’s best to talk with a healthcare professional before using it as a treatment option.

The recommended dosage of zinc is different for adults and children. Be sure to read the dosage instructions carefully before giving zinc to your child.

Vitamin C

A 2013 review of clinical trials found that regular vitamin C supplementation doesn’t decrease your likelihood of getting a cold. It can, however, sometimes reduce the duration or severity of your cold.

It should be noted, though, that in these trials, vitamin C didn’t have much of an effect when taken after the onset of symptoms.

Echinacea

There’s mixed evidence regarding the effectiveness of echinacea for treating colds.

A 2014 review of clinical trials found that echinacea only affected the duration of a cold in 1 in 7 trials reviewed.

It can take about 7 to 10 days to fully recover from a cold. You’ll typically start to notice that your symptoms gradually improve as time passes.

A cough due to a cold may linger in some people. On average, a cough can last about 18 days (almost 3 weeks) before going away.

Some people are at an increased risk of cold complications such as:

bronchitis or pneumonia
sinus infections
ear infections
throat infections

This includes people with conditions such as:

asthma
chronic obstructive pulmonary disease (COPD)
a weakened immune system

Be sure to see your doctor or a healthcare professional if you or your child:

have symptoms that last longer than 10 days without improving, are very severe, or begin to improve but then return
have a fever higher than 103°F (39.4°C) (adult), above 102°F (38.9°C) (child), or above 100.4°F (38°C) (infant younger than 3 months)
have a fever of 100.4°F (38°C) or higher that lasts longer than 3 days
experience difficulty breathing or have shortness of breath
notice that underlying health conditions have worsened

According to the Centers for Disease Control and Prevention (CDC) , colds are one of the main reasons people miss school or work. Adults typically have an average of 2 to 3 colds per year, while children have even more.

There are a few steps that you can take to prevent coming down with a cold.

Prevention tips

Wash your hands. Since cold viruses can be present on your hands, try to wash your hands regularly for 20 seconds with soap and warm water. If soap and water aren’t available, use an alcohol-based hand sanitizer. Be sure to wash your hands:
- before touching your mouth, nose, or eyes
- after being out and about in public spaces
- after using the bathroom or changing a diaper
- before and after eating
- before and after caring for someone who is sick
If you’re currently sick with a cold, there are steps you can take to prevent passing it to others.

If you have a cold:
- Stay home. If you develop a cold, plan to stay home until you feel better.
- Wash your hands. To prevent the cold virus from lingering on your hands, make sure to wash your hands with soap and warm water after you blow your nose, cough, or sneeze.
- Cover your mouth and nose when you cough or sneeze. Avoid coughing or sneezing directly into your hands. Instead, use a tissue or the crook of your elbow. Dispose of used tissues promptly.
- Keep your distance. Avoid having close contact with other people until you recover. Try not to shake hands, hug, or stand too close to other people while you have cold symptoms.
- Disinfect surfaces. Regularly disinfect high-touch surfaces around your house. A few examples include doorknobs, countertops, kitchen appliances, phones, and computer keyboards.
The common cold is a contagious viral infection with an incubation period of 1 to 3 days. This means it could take up to 3 days for you to notice symptoms after being exposed to the virus.

Colds are contagious during their incubation period, which means that you can potentially pass a cold virus to others without knowing it. You remain contagious as long as you’re experiencing cold symptoms.

There’s no cure for a cold, but taking oral zinc at the first sign of a cold or regularly taking a vitamin C supplement may help to shorten the duration of a cold.

In most cases, you’ll simply need to let your body rest as it fights the infection and begins the recovery process. Drinking plenty of fluids and taking OTC medications to ease symptoms can help you feel better during this time.

Last medically reviewed on December 10, 2021

How we reviewed this article:

Healthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.
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Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available.

How Long Am I Contagious?

You can actually infect someone before you start feeling symptoms of the flu.You are most contagious in the 3 to 4 days after you start to feel sick, but you remain contagious as long as you have symptoms. Usually this is about a week, but it could be a few days more for children or people with weak immune systems. You can also pass it on a day or so before you start feeling sick. Some people can transfer the virus without ever getting symptoms.

Cold

2/16

A cold often starts with a runny nose and sore throat, followed by coughing and sneezing. You’re contagious a day or two before this starts and for as long as you feel sick, usually a week or two. It may be longer if you already have breathing problems or a weak immune system. You’re more likely to infect others during in the first few days, when symptoms are at their worst.

COVID-19

3/16

Caused by the virus SARS-CoV-2, this infection can cause fever, chills, trouble breathing, body aches, fatigue, cough, and nausea. But you can spread the virus 2 to 3 days before you notice any of these signs. You can also pass it on to others if you aren’t showing symptoms. If you are sick, you can be contagious for a while, so stay away from others until your symptoms improve and you’ve been without a fever for 3 days in a row. If you test positive for the virus but don’t have symptoms, it’s best to keep away from others for 10 days to see if you get sick.

Mononucleosis

4/16

This viral illness is also known as the kissing disease because that’s one of the ways you can pass it on to others. You might be contagious from the moment you’re infected, and that isn’t good because it often takes 4-7 weeks before you notice any of its flu-like symptoms. You can spread the disease the entire time you have it. Even once you feel better, you may be able to pass on the virus for as long as 18 months.

Norovirus

5/16

It can cause diarrhea, nausea, stomach pain, vomiting, headache, fever, and body aches. Just a few norovirus particles (your body sheds billions) can infect another person, most often by touching food or kitchen tools. You’re most contagious when you’re sick and for a few days after, but you can still spread it for 2 weeks or more after you feel better. Clean your hands regularly and wash food thoroughly to prevent spreading norovirus.

Conjunctivitis (Pinkeye)

6/16

Germs, irritants, or allergens can inflame the tissue, known as the conjunctiva, that lines your inner eyelid and the whites of your eyes. Your eye might be red, itchy, or watery. When it’s caused by bacteria, your eye may fill with pus. You can spread it to others for as long as you notice symptoms or for 24 hours after you start antibiotic drops. The milder viral form is contagious while you have symptoms and for a day or two before.

Measles

7/16

Vaccines make it rare in the U.S., but worldwide, thousands die yearly from this virus, most under age 5. It causes a dry cough, sore throat, runny nose, fever, and a distinctive rash of tiny red bumps, some raised. It spreads easily, hanging around in the air for 2 hours after you cough or sneeze. Once the rash appears, you’ve already been contagious for 4 days. You’ll stay that way for 4 days after it goes away.

Hand, Foot, and Mouth Disease

8/16

This virus, common in young children, causes a red rash on the hands, feet, or bottom. It also may cause a fever, sore throat, and painful, blistering sores in the mouth. You’re most contagious the first week, but some people can still pass it on for weeks. You can get it from a simple cough, sneeze, or contact with spit or open blisters. It’s best to keep yourself or your child home if you have hand, foot, and mouth disease.

Whooping Cough

9/16

Most dangerous to babies, this bacterial infection has reappeared more recently in all ages because of missed vaccinations and booster shots. The “whoop” refers to the telltale sound your chest makes as you breathe in after a coughing fit, though this may not happen in teens or adults. You can pass it on, mostly through tiny droplets in the air, for 2 to 3 weeks after the cough starts. Antibiotics may be able to shorten this time.

Impetigo

10/16

Young kids most often get these contagious sores on the face, neck, hands, or butt. They may be unbroken, or wet and red, or crusty and yellow. The bacteria often get in when you cut, scrape, or irritate the skin. You can transfer it to other people who touch the sores. Proper handwashing could help prevent it. Doctors use antibiotics in a pill or ointment to kill the bacteria.

MRSA

11/16

Skin infection with MRSA, a type of staph bacteria called Staphylococcus aureus, could be serious because it doesn’t respond to several antibiotics. You may have sores, bumps, or a swollen cut with pus inside. You can give a MRSA infection to someone if they make contact with your infection or anything that touched it. If you have a MRSA infection, complete all treatments and follow your doctor’s instructions so it won’t spread to others.

E. coli

12/16

It’s one of the most common causes of bacterial diarrhea, but there are others like campylobacter, salmonella, and shigella. You can pass these bacteria on to others when you touch food or surfaces with unwashed hands, or by swimming in a pool when you’ve been sick. It’s contagious while you’re sick, and sometimes longer. Regular bathing and handwashing are the best ways to protect others and yourself.

Chest Cold

13/16

Sometimes called bronchitis, it happens when regular cold symptoms move down to inflame your lungs, which makes you cough. But whether it’s a cold, the flu, or some other virus, the rule of thumb is the same: You’re contagious for as long as you have symptoms, and maybe a little bit longer. To stop the spread, keep your hands clean at all times and cover your mouth when you sneeze or cough.

Chickenpox

14/16

This viral rash causes a fever or sore throat and telltale itchy spots all over your body. A new vaccine means most kids don’t get it anymore. But if yours do, it’s very contagious. Keep them home until all the sores crust over.

Shingles

15/16

Once you’ve had chickenpox, the virus lives on inside your body. It may come back later, often in middle age, as shingles, a painful, blistering rash. The chickenpox virus lives inside these blisters. Although the liquid that oozes out can’t give someone else shingles, it can give them chickenpox if they haven’t had it and haven’t been vaccinated.

Poison Ivy

16/16

Like its cousins, poison oak and poison sumac, its leaves have an oily sap (urushiol) that can make your skin red, swollen, and itchy. Until you wash it off with soap and water, you can pass the oil to someone who touches it, or to other parts of your body. Cool showers and calamine lotion can help relieve the itch. It should be gone in a week or two.

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National Health Service (U.K.): “How long is someone infectious after a viral infection?”

CDC: “Chest Cold (Acute Bronchitis),” “Common Colds: Protect Yourself and Others,” “E. coli (Escherichia coli),” “Hand, Foot, and Mouth Disease,” Influenza (flu),” “Measles (Rubeola),” “Methicillin-resistant Staphylococcus aureus (MRSA),” “Norovirus,” “Pertussis (Whooping Cough),” “Pregnancy and Whooping Cough,” “Prevent the Spread of Norovirus.”

Cedars-Sinai Hospital: “Am I Still Contagious?”

The Nemours Foundation: “Chickenpox,” “E. Coli,” “Impetigo,” “Mononucleosis,” “Pinkeye (Conjunctivitis),” “Whooping Cough (Pertussis).”

Brenner Children’s Hospital: “How Long Is Mono Contagious?”

American Optometric Association: “Conjunctivitis.”

Mayo Clinic: “Hand-foot-and-mouth disease,” “Measles,” “Poison ivy rash,” “Shingles.”

Harvard Health Publishing: “That nagging cough.”

Alameda County Public Health Department: “Pertussis (Whooping Cough).”

Nebraska Department of Health and Human Services: “FAQs about MRSA.”

Cleveland Clinic: “Poison Plants: Poison Ivy, Poison Oak & Poison Sumac,” “Norovirus.”

John Hopkins Medicine: “What is Coronavirus?”

Nature Medicine: “Temporal Dynamics in viral shedding and transmissibility of COVID-19.”

How Long Am I Contagious