We all know that a cold or the flu can be contagious, which is why being near a coworker or fellow commuter who’s coughing and sneezing is a cue to run for the hand sanitizer. But the answer to whether bronchitis is contagious is not quite as straightforward.
Bronchitis is an inflammation of the lining of the bronchial tubes, which are the passageways that carry air to and from your lungs. (1) Bronchitis can either be chronic or acute. Chronic bronchitis is characterized by repeated flare-ups of symptoms that don’t ever go away; this is one of the conditions included in chronic obstructive pulmonary disease, or COPD. It is not contagious. (2)
Acute bronchitis is often caused by a virus (such as a cold or the flu) and typically gets better after a week or two, though a cough may persist for weeks after the infection is over. The germs that cause acute bronchitis are often extremely contagious. (3) But because “acute bronchitis” by definition refers to a symptom (inflammation of the bronchial tubes), technically it is in and of itself not contagious — but the viruses that commonly cause bronchitis are.
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“Most respiratory viruses are highly contagious,” explains Fernando Holguin, MD, a professor of medicine at the University of Colorado School of Medicine. (3,4) Some of the more common viruses that can lead to bronchitis include influenza virus A and B, parainfluenza, and rhinovirus, among others. (5)
If You Have Bronchitis, You Can Get People Around You Sick
Coughing, a hallmark symptom of bronchitis, is one of the main ways the germs that cause acute bronchitis travel from one person to another. When someone with bronchitis coughs, sneezes, or even talks, droplets of saliva or mucus containing the virus that caused their infection can fly through the air. The airborne virus can then come into direct contact with someone else, perhaps going right into their eyes or mouth; or it could land on a surface that is then touched by an uninfected individual, who then touches his or her eyes, nose, or mouth, spreading the infection. (6)
This is why it’s crucial for someone who has bronchitis or a respiratory illness to always cough into the crook of their elbow or a tissue and wash their hands frequently, especially after sneezing or coughing. (3,6,8)
It’s worth noting that for some people who come in contact with the germ, bronchitis develops. Others develop milder symptoms of a cold. And others won’t experience symptoms at all. (3,9)
Other important points to know about why and when bronchitis is contagious are:
How Long Can Someone With Bronchitis Be Contagious?
How long you are contagious when you have bronchitis can vary depending on the type of infection, how active symptoms are, and your overall health. When it comes to colds, people are the most contagious for the first two to three days of the infection, Dr. Holguin says. With the flu, people are most contagious in the first three to four days after the onset of their illness, according to the Centers for Disease Control and Prevention (CDC). (10)
To make sure they are no longer contagious, the CDC advises anyone with a fever to stay home from school or work for at least 24 hours after their temperature has gone down without any fever-reducing medication, says Ralph Gonzales, MD, associate dean for clinical innovation for UCSF Health in San Francisco. (11)
Is Bronchitis Contagious After Taking Antibiotics?
Doctors usually do not prescribe antibiotics for bronchitis since most cases are caused by a virus (and antibiotics cannot kill viruses).
But if bronchitis is caused by a bacteria and it’s not improving, your doctor may prescribe an antibiotic. After 24 hours of starting the medication, you should no longer be contagious. (12,13)
Is Bronchitis Contagious for Babies?
Infants and babies under 2 years of age more commonly get an infection called bronchiolitis, which causes the tiny breathing tubes of the lungs, called bronchioles, to become swollen and inflamed and filled with mucus, restricting airflow and making it difficult for babies to breathe. (Bronchitis, in contrast, affects the larger central airways, called the bronchi, and is more common in older children and adults.)
Bronchiolitis occurs more often in infants than older children because their airways are very small and can become blocked more easily. (14,15,16,17) There are several viruses that can cause bronchiolitis, including those that cause the common cold and the flu.
Viruses that cause bronchiolitis are highly contagious, and are transmitted through droplets in the air though sneezes and coughs, and can also be spread when babies touch toys and other objects and then bring their hands to their mouth, nose, and eyes. (15,16,17) Younger infants are more vulnerable, and the best way to guard against viruses that can cause bronchiolitis (for all babies) is to wash your hands often, especially before touching your baby. Also keep infants away from anyone who has a cold or cough.
Here’s How to Avoid Bronchitis — Starting With the Germs That Cause It
There’s no way to completely eliminate your risk of developing bronchitis, but you can take measures to reduce your risk. And if you’re someone who is at an increased risk of developing bronchitis (due to asthma, age, or other factors), following these steps may be even more important to help stay well: (12)
1. Wash Your Hands Thoroughly and Often
One of the best ways to reduce your risk of getting bronchitis is to avoid getting a viral illness in the first place. And one of the best ways to avoid getting an infection is by washing your hands, especially before, during, and after preparing food and before eating; after blowing your nose; and before and after taking care of someone who is sick.
And yes, there is a right way to wash your hands: Get a good lather and scrub your hands — including the backs of the hands, between the fingers, and under the nails — for at least 20 seconds, or the time it takes to hum “Happy Birthday” from start to end two times.
If washing with soap and water isn’t possible, clean your hands with a hand sanitizer that’s at least 60 percent alcohol. (3,18,19,20)
2. Avoid Touching Your Face
In addition to good handwashing habits, it’s a good idea to remember not to touch your eyes, nose, or mouth with your hands, says Dr. Gonzales. “Keep your hands away and wash numerous times a day,” says Gonzales. (18)
3. Get a Flu Shot
The flu is a common cause of bronchitis. Getting an annual flu shot can lower your risk of getting sick. Research has shown that if you do get sick after getting the flu shot, your illness may be milder, which can help lower your risk of developing bronchitis. (3,21)
4. Keep Your Immune System Strong
Get plenty of sleep each night, eat a healthy diet, exercise, and keep stress in check. Research has shown that feeling more psychological stress can increase your risk of getting a cold. (22) But things like eating a healthy diet and exercising can help keep your immune system healthy, helping your body ward off illness. (23) “Exercise keeps everything flowing and circulating, which can help maintain a robust immune system,” Gonzales says.
5. Don’t Overexert Yourself
Moderate exercise is beneficial for immune system health, but overdoing it may actually be counterproductive, especially during cold and flu season, Gonzales says. While previous research has shown moderate-intensity exercise can improve immune function and potentially help reduce the risk of getting a viral respiratory infection, prolonged and intense exercise may actually suppress immune system function. (24)
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6. Clean Surfaces
The flu virus can live on a surface for up to 48 hours after someone who is infected touches it. When someone who doesn’t have the flu touches that surface and then touches their own eyes or mouth, they can become infected.
To prevent illness from spreading, especially during cold and flu season, be sure to regularly wipe down commonly touched surfaces, like doorknobs and refrigerator handles. This is especially important if someone in the family has bronchitis or is coming down with a cold or the flu. (25)
7. Don’t Smoke
Smoking can increase your risk for developing bronchitis. If you smoke, stop, and avoid exposure to secondhand smoke. (1)
8. Consider Vitamin C and Zinc
When it comes to supplements that may help ward off viral infections, two may be worth considering: vitamin C and zinc.
A meta-analysis from 2013 that looked at 29 studies found that vitamin C may reduce the severity and duration of colds in physically active people. (26) The data is still unclear about whether or not the general population benefits from getting extra vitamin C, but experts say for otherwise healthy individuals, extra vitamin C is safe to try, as extra vitamin C not used by the body gets excreted in urine. (27) Gonzales suggests taking 1,000 milligrams (mg) per day during cold and flu season, preventively.
As for zinc, there is substantial evidence showing that zinc lozenges may reduce the duration of a cold when taken within 24 hours after symptoms start, says Holguin. (28) There are not necessarily generally accepted guidelines on what dose of zinc works best, but a 2017 review found that a dose of about 80 mg per day was effective and safe (when taken for a two-year period). (29)
9. Consider Wearing a Face Mask
If you have COPD, asthma, or another lung condition, wearing a face mask if you may be exposed to dust or fumes, or if you’re going to be near crowds of people, can help reduce your risk of exposure to irritants and viruses. (1,3)