Bronchitis vs. Pneumonia: What Are the Differences?

If you’ve experienced a lingering cough that seems to come from deep in your chest, you may have wondered: Could I have bronchitis or pneumonia?

Coughs are a common symptom of respiratory infections like a cold or the flu — your body’s way of naturally clearing irritants out of your air passages to help prevent infection. (1)

Signs and Symptoms That Mean You Have Bronchitis

But a cough that won’t go away even after your sore throat, fever, and other symptoms have gotten better, and that’s accompanied by wheezing or shortness of breath, may indicate that you’re dealing with something more serious, like bronchitis or pneumonia. (1,2)

Given how many symptoms the two respiratory conditions share, it’s not surprising that bronchitis is often mistaken for pneumonia and vice versa. Bronchitis that’s thought to have turned into pneumonia may actually have been pneumonia all along. It’s also common for people to think that bronchitis can often turn into pneumonia, but in reality, this is not the case for most people, explains Ralph Gonzales, MD, the associate dean for clinical innovation and chief innovation officer for the University of San Francisco Health and an internal medicine specialist. “What we call bronchitis may sometimes be pneumonia,” he says.

Acute bronchitis is a condition in which the lining of your bronchial tubes (the passages that carry air to and from your lungs) becomes inflamed. This condition usually develops as a result of a viral infection like a cold or the flu, and it typically gets better in about one to two weeks. (This is different from chronic bronchitis, which is a condition that does not go away and is marked by a recurring cough and other symptoms that can be managed but not cured.) (3,4)

Pneumonia is an infection in one or both of the lungs that can be caused by bacteria, viruses, or fungi. When you have pneumonia, the air sacs of the lungs (alveoli) fill up with fluid or pus. While anyone can get pneumonia, some people — such as children, the elderly, people with asthma, and individuals with chronic disease — are at an increased risk of developing this lung condition. (1,5,6)

RELATED: Everything You Need to Know About Pneumonia in Kids

Both bronchitis and pneumonia involve inflammation in the chest (though that inflammation occurs in different parts of the chest for each one). And both conditions share some common symptoms: (1,2,5,7,8)

• Cough (often accompanied by the production of mucus)
• Fatigue
• Shortness of breath that can get worse when you’re active
• Fever and chills

Bronchitis can also, however, bring on chest discomfort and wheezing.

And pneumonia can bring on these symptoms not usually linked to bronchitis: (7,8,9)

• Excessive sweating and clammy skin
• Suddenly feeling worse after cold or flu symptoms go away
• Sharp pain in the chest, especially when breathing deeply or coughing
• Headache
• Loss of appetite
• Lack of energy
• Confusion
• Nausea, diarrhea, and vomiting

While symptoms for either bronchitis or pneumonia can range from mild to serious enough to require hospitalization, symptoms such as fever, breathing problems, and chest pain tend to be more severe with pneumonia.

In people with pneumonia, the alveoli fill with pus and other fluids and prevent oxygen from reaching the bloodstream; when there’s too little oxygen in the blood, the body cannot function properly, increasing the risk of death. (1,10)

While bronchitis and pneumonia both have to do with chest inflammation, they are separate and different conditions that happen independent of each other — meaning one doesn’t necessarily cause the other, explains Fernando Holguin, MD, a professor of medicine at the University of Colorado School of Medicine and the director of the asthma clinical research program at the Center for Lungs and Breathing at the University of Colorado Hospital, both in Aurora. “And you can have both bronchitis and pneumonia at the same time,” Dr. Holguin says.

That said, in some cases bronchitis does turn into (thereby causing) pneumonia. This occurs when either the infection spreads from the bronchial tubes to the lungs or a secondary infection occurs. While either scenario is rare, it tends to happen more often in people who have a weakened immune system or another condition that makes them more susceptible to infection.

Some people are at risk of bronchitis turning into pneumonia: (11,12)

• Those with a weakened immune system
• Smokers
• Individuals who have a chronic health condition, such as heart, kidney, or liver disease
• People with an underlying lung disease
• Older adults
• Young children
• Pregnant women

While doctors aren’t sure exactly how having a viral infection may make someone more prone to developing pneumonia or another secondary infection, studies have pointed to some theories.

“Animal models have shown that when you have an infection, it weakens your body’s ability to protect against bacterial infection,” Dr. Gonzales explains. (13) Doctors also think that the epithelial tissue of the airway, which serves as a barrier against viruses and bacteria, can become compromised following a viral infection, making it easier for bacteria to invade, Gonzales adds. (14)

If you see any of these symptoms, call your doctor; they may be an indication that your bronchitis has turned into pneumonia: (5,9,11)

• High fever (higher than 100.4 degrees Fahrenheit) that lasts at least a couple of days
• Chest pain (especially if it develops suddenly and is on one side — a common sign of pneumonia)
• Cough that lasts more than three weeks
• Blood in mucus
• Shortness of breath, even with only mild or moderate activities
• Shaking chills
• Rapid breathing (breathing faster to try to get air)
• Drowsiness or confusion

Besides reviewing your symptoms, your doctor may use a simple chest X-ray to diagnose pneumonia.

Most cases of respiratory infections like a cold or the flu, and related bronchitis, do not lead to pneumonia. And in healthy people, pneumonia can usually be treated effectively. But for those who are at an increased risk for developing pneumonia after bronchitis (such as the elderly, people with chronic health conditions, and pregnant women), pneumonia can be very dangerous, even deadly. (10)

The best way to prevent a secondary infection is to reduce your risk of getting a viral or bacterial infection in the first place. Wash your hands regularly, avoid touching your face, and if a family member is sick, don’t share utensils and clean common areas regularly (the flu virus can live on a surface for up to 48 hours, according to the Centers for Disease Control and Prevention). (14,15)

Doctors also stress the importance of getting a flu vaccine and pneumococcal vaccine to prevent a viral infection that can lead to pneumonia. (10)

You can also try to prevent getting a secondary infection by taking care of yourself and treating your bronchitis symptoms, which includes these actions: (2,16)

• Getting sleep and staying rested
• Not smoking and minimizing your exposure to secondhand smoke
• Avoiding using housecleaning products until you recover
• Avoiding strenuous exercise for a few days
• Avoiding cold air, which, like certain chemicals, can be irritating to your airway passages
• Using a humidifier

Treatment of pneumonia that has developed after bronchitis can vary depending on factors like age, severity of symptoms, and medical history. “If your symptoms are severe, your doctor may recommend hospitalization,” says Holguin.

If you’re not experiencing breathing difficulties or other serious symptoms and your pneumonia is determined to be bacterial, you may be prescribed an oral antibiotic. (17)

Your doctor may also test you for other infections, such as the flu, and depending on your symptoms and test results, recommend an antiviral medication, says Holguin. (17,18,19)

If your doctor determines that your pneumonia can be treated at home, they may suggest the following: (17)

• Drinking plenty of fluids, which can help loosen phlegm and clear it out of your body
• Getting lots of rest (not going to work and enlisting someone to help with household chores)
• Taking ibuprofen (Advil) or acetaminophen (Tylenol) for fever or chest pain

If hospitalized for pneumonia, you may be given these treatments: (17,18,19)

• Oxygen therapy and other breathing treatments
• Fluids (possibly intravenously as well as by mouth)
• Antimicrobial agents (either antibiotics or antiviral medications)