Bronchitis is inflammation of the tubes that carry air to your lungs

Your lungs have small tubes called bronchi that branch like a tree, carrying air deeper into your lungs with each breath. When these tubes become inflamed and swollen, they produce extra mucus. That swelling and mucus is bronchitis. The inflammation makes you cough — often for weeks — because your body is trying to clear the mucus out.

Most bronchitis starts after a cold or flu virus. Your immune system fights the virus, but the inflammation in your airways can linger even after the infection clears. This is why you can cough for three weeks or longer after feeling better from a cold.

Bronchitis is different from pneumonia, even though both affect your lungs. With pneumonia, the infection reaches the air sacs at the end of the bronchi, where oxygen enters your blood. With bronchitis, the inflammation stays in the tubes themselves. That distinction matters because it changes how doctors treat it and how serious it is.

Key Takeaways

  • Bronchitis is swelling in the tubes that carry air to your lungs, usually triggered by a viral infection like a cold or flu.
  • The main symptom is a persistent cough that can last three weeks or longer, often bringing up mucus or phlegm.
  • A doctor can usually diagnose bronchitis by listening to your lungs with a stethoscope and hearing specific sounds, without needing imaging or blood tests.
  • Most cases of bronchitis get better on their own with rest, fluids, and time, though a cough can take weeks to fully resolve.
  • Antibiotics do not treat viral bronchitis, but a doctor may prescribe other medications to ease coughing or help you breathe more easily.

The two types: acute and chronic

Acute bronchitis is what most people get after a cold or flu. It comes on suddenly, lasts a few weeks, and then goes away. The cough is usually the last symptom to disappear — you might feel fine otherwise but still cough for three to four weeks.

Chronic bronchitis is different. It is a long-term condition where the inflammation does not go away. People with chronic bronchitis cough most days for at least three months, often for years. Chronic bronchitis is actually one type of a larger condition called chronic obstructive pulmonary disease, or COPD. It is usually caused by smoking or long-term exposure to irritating substances like dust or pollution.

This article focuses on acute bronchitis, which is what most people experience. If you have a cough that lasts longer than a few weeks, or if you smoke or have had long-term exposure to irritants, talk to your doctor about whether chronic bronchitis might be involved.

How doctors recognize bronchitis

Your doctor will start by asking about your cough — when it started, whether you bring up mucus, and what you were doing before it began. They will ask if you had a recent cold or flu, and whether anyone around you has been sick.

Then they will listen to your lungs with a stethoscope. Bronchitis makes a specific sound — often a crackling or wheezing noise — that a doctor learns to recognize. In most cases, that is enough to diagnose it. You usually do not need a chest X-ray or blood test unless your doctor suspects something else is going on, like pneumonia or a bacterial infection.

If you are coughing up blood, having trouble breathing, or are very short of breath, your doctor may order a chest X-ray to rule out pneumonia or other complications. But for a straightforward case of bronchitis, the stethoscope exam is the main diagnostic tool.

Why your cough lasts so long

The cough from bronchitis can feel like it never ends. You might feel better in a week or two — your fever is gone, your energy returns — but the cough stays. This frustrates many people because they feel well otherwise.

The reason is that the inflammation in your airways takes time to heal. Even after the virus is gone and your immune system has won the fight, the swollen tissue and extra mucus remain. Your body keeps coughing to try to clear it out. Gradually, over two to four weeks, the swelling goes down and the mucus decreases, and the cough fades.

Some people cough longer than others. Smokers, people with asthma, and people over 65 often have a cough that lasts six weeks or more. If your cough is still there after eight weeks, or if it gets worse instead of better, see your doctor again.

What actually helps, and what does not

There is no cure for viral bronchitis — antibiotics do not work because a virus caused it, not bacteria. Your body has to heal itself. But several things make the process easier.

Rest and fluids are the foundation. Your immune system needs energy to repair the inflammation, and staying hydrated helps loosen the mucus so you can cough it up more easily. Drink water, warm tea, or broth throughout the day.

Cough medicines can help you sleep or get through your day. Dextromethorphan (the "DM" in many over-the-counter cough syrups) suppresses the cough reflex. Guaifenesin (found in Mucinex and similar products) thins the mucus so it is easier to cough up. You can use these together or separately depending on whether you want to stop coughing or cough more productively.

Inhalers or nebulizers may be prescribed if you are wheezing or having trouble breathing. These deliver medication directly to your airways to open them up and reduce inflammation. Your doctor will tell you if you need one.

Honey has some evidence behind it — a spoonful of honey can soothe your throat and may reduce cough frequency, especially in children over one year old. Do not give honey to babies under one year because of the risk of botulism.

Antibiotics do not help unless your doctor finds evidence of a bacterial infection on top of the viral bronchitis. This is uncommon, and your doctor will tell you if they are prescribing antibiotics for this reason.

When to see a doctor

You do not always need to see a doctor for bronchitis. Many people recover fine with rest and time. But see a doctor if any of these apply:

  • You are coughing up blood or blood-tinged mucus.
  • You are short of breath or wheezing, especially if it is getting worse.
  • You have a high fever (over 101°F or 38.3°C) that lasts more than a few days.
  • Your cough lasts longer than three weeks.
  • You are over 65, have heart disease, diabetes, or a weakened immune system.
  • You are pregnant.
  • Your symptoms improve and then suddenly get worse again.

These situations suggest either that bronchitis is more severe than typical, or that something else is happening alongside it. Your doctor can examine you and decide whether you need additional treatment or testing.

How to lower your risk

Since most bronchitis follows a cold or flu, the best prevention is avoiding those infections in the first place. Wash your hands regularly, especially before eating and after being around sick people. If you are around someone with a cold or flu, keep your distance when they cough or sneeze.

The flu vaccine reduces your risk of getting the flu, which means you are less likely to develop bronchitis afterward. The vaccine is updated each year and is available in the fall.

If you smoke, quitting is the single most important step you can take. Smoking damages the lining of your airways and makes bronchitis more likely and more severe. It also makes chronic bronchitis more likely to develop.

If you are exposed to dust, fumes, or pollution at work, use protective equipment like a mask if your employer provides it. Long-term exposure to these irritants can lead to chronic bronchitis over time.

Frequently Asked Questions

Is bronchitis contagious?

The virus that causes bronchitis is contagious, but bronchitis itself is not. You can spread the cold or flu virus to others, and they might develop bronchitis or a different respiratory infection. Once you have had bronchitis for a few days, you are usually less contagious, but you can still spread the virus if you cough or sneeze on someone.

Can bronchitis turn into pneumonia?

Bronchitis and pneumonia are different conditions, but they can occur together. If the infection spreads from your bronchi down into the air sacs of your lungs, you can develop pneumonia on top of bronchitis. Signs of pneumonia include high fever, shortness of breath, chest pain, and coughing up mucus that is rust-colored or contains blood. See a doctor right away if you develop these symptoms.

Why do I still have a cough after two weeks if I feel better?

The inflammation in your airways takes longer to heal than the rest of your body. You recover from the infection and feel well, but the swollen tissue and extra mucus remain, triggering a cough. This is normal and does not mean something is wrong. The cough should gradually improve over the next two to four weeks.

Do I need an antibiotic for bronchitis?

Most bronchitis is caused by viruses, and antibiotics do not work against viruses. Your doctor will only prescribe an antibiotic if they believe a bacterial infection is also present, which is uncommon. Taking antibiotics when you do not need them can lead to antibiotic resistance, making them less effective for future infections.