Bronchitis is the inflammation (-itis) of the lining of the bronchial tubes (bronch-). These are the main airways that branch off from your windpipe (trachea) and carry air into and out of your lungs. When the lining of these tubes becomes irritated and inflamed, it swells and produces an excess of mucus. This leads to the characteristic coughing and phlegm production of the illness.

To understand the difference between the two main types, it is helpful to use an analogy. Think of your lungs’ airways as the smooth, open branches of a tree.

• In acute bronchitis, it is as if a temporary, mild wildfire has swept through the branches after a storm (a viral cold). The branches are irritated, inflamed, and covered in soot and debris (mucus), causing you to cough forcefully to clear them out. After a couple of weeks, the fire goes out, the inflammation subsides, and the branches heal completely.
• In chronic bronchitis, years of exposure to a constant irritant like cigarette smoke has permanently damaged the branches. They have become chronically inflamed, thickened, and narrowed, and they constantly produce an excess of mucus. In this case, the “fire” is a low-level, smoldering burn that never truly goes out, leading to a daily, long-term cough and progressive breathing difficulties.

In my experience, patients often describe it as a “bad chest cold” that just won’t go away, bronchitis involves inflammation of the bronchial tubes, causing a persistent cough.

The causes of acute and chronic bronchitis are fundamentally different.

Causes of Acute Bronchitis

In over 90% of cases in otherwise healthy adults, acute bronchitis is caused by a virus. It is typically caused by the same viruses that are responsible for the common cold and the flu. These include:

• Rhinovirus
• Influenza A and B
• Coronavirus (including those that cause the common cold)
• Respiratory Syncytial Virus (RSV)
• Human metapneumovirus

Because it is viral, acute bronchitis is not a bacterial infection. In a small number of cases, bacteria can be the cause, but this is uncommon. Acute bronchitis can also be triggered by inhaling irritants like tobacco smoke, dust, or chemical fumes.

Causes of Chronic Bronchitis

Chronic bronchitis is the result of long-term, repeated irritation and damage to the bronchial tube lining.

• Cigarette Smoking: This is, by far, the overwhelming cause of chronic bronchitis. Most people diagnosed with chronic bronchitis are current or former smokers. Constant inhalation of toxic chemicals from smoke causes irreversible airway damage.
• Long-Term Exposure to Irritants: Breathing in other lung irritants over a long period can also cause or contribute to chronic bronchitis. This includes exposure to:
  • Secondhand smoke.
  • Severe and persistent air pollution.
  • Occupational dusts and fumes from industries like coal mining, grain handling, or textiles.

Clinically, most acute cases I’ve seen are viral, caused by the same viruses responsible for colds and flu. Chronic bronchitis, on the other hand, is commonly linked to smoking.

How a person develops bronchitis depends entirely on the type.

• Acute Bronchitis: You get acute bronchitis by catching one of the common respiratory viruses that cause it. It is contagious and spreads easily from person to person through respiratory droplets when an infected person coughs or sneezes.
• Chronic Bronchitis: This condition is not contagious. You develop it due to long-term damage to your own airways from years of exposure to irritants, most commonly cigarette smoke.

Clinically, I often see chronic bronchitis in long-term smokers or those exposed to occupational irritants. Repeated damage to airway lining leads to ongoing inflammation and mucus buildup.

While both conditions involve a cough, the pattern and accompanying symptoms are very different.

Signs and Symptoms of Acute Bronchitis

Acute bronchitis often develops during or after a common cold.

• The hallmark symptom is a persistent, hacking cough. The cough may be dry at first but often becomes productive, meaning you cough up clear, yellow, or greenish mucus.
• Chest discomfort, soreness, or a feeling of tightness.
• Fatigue and a general feeling of being unwell.
• Mild headache and body aches.
• A low-grade fever.
• The most important feature is that the cough is the last symptom to resolve and can linger for three to four weeks, long after the other cold symptoms have disappeared.

Signs and Symptoms of Chronic Bronchitis

Chronic bronchitis is defined by its long-term nature. The primary symptom is:

• A chronic, daily, productive cough that lasts at least three months of the year, for two or more consecutive years.
• Production of sputum (mucus) most days.
• Frequent throat clearing.
• As the underlying COPD progresses, other symptoms develop, including:
  • Shortness of breath (dyspnea), especially with physical activity.
  • Wheezing.
  • Frequent respiratory infections or “chest colds” that last longer than usual.

Patients typically complain of a lingering cough, often with mucus, chest tightness, low-grade fever, and fatigue. Symptoms can last weeks, even if the infection is gone.

A doctor can often diagnose bronchitis based on a physical exam and a discussion of your symptoms. The primary goal of the diagnostic process is often to rule out other, more serious lung conditions.

Diagnosing Acute Bronchitis

• Clinical Diagnosis: The diagnosis is almost always made based on your symptoms and a physical examination. A doctor will listen to your chest with a stethoscope to check for wheezing or other sounds.
• Chest X-ray: A doctor may order a chest X-ray not to diagnose bronchitis, but to rule out pneumonia. Pneumonia is an infection of the lung tissue itself, whereas bronchitis is an inflammation of the airways. If you have a high fever, a rapid heart rate, or abnormal sounds on your lung exam, a chest X-ray is important to make sure you do not have pneumonia, which requires different treatment.

Diagnosing Chronic Bronchitis

• Clinical Definition: The diagnosis is based on the patient’s history fitting the clinical definition: a productive cough for at least three months a year for two consecutive years, along with a history of significant exposure (usually smoking).
• Pulmonary Function Tests (PFTs) or Spirometry: This is the key test to confirm the presence of COPD. You will be asked to take a deep breath and blow out as hard and fast as you can into a tube connected to a machine. This test measures how much air your lungs can hold and how quickly you can exhale, which can reveal the airway obstruction that is characteristic of COPD.
• A chest X-ray is also typically performed.

Clinically, I usually make the diagnosis based on symptoms and exam, chest X-rays or labs are only needed if pneumonia is suspected or the patient is high-risk.

The treatments for acute and chronic bronchitis are completely different, which is why a correct diagnosis is so important.

How Acute Bronchitis is Treated?

Antibiotics do not work for acute bronchitis. Since over 90% of cases are caused by viruses, antibiotics will not help you get better faster and can cause unnecessary side effects. Prescribing antibiotics for acute bronchitis is a major driver of antibiotic resistance, a serious global health problem.

The treatment for acute bronchitis is entirely supportive and focused on relieving symptoms while your body fights off the virus.

• Rest and Fluids: Get plenty of rest and drink lots of fluids to stay hydrated.
• Humidifier: Using a cool-mist humidifier or breathing in steam from a shower can help to soothe irritated airways.
• Pain Relievers: Over-the-counter medications like acetaminophen or ibuprofen can help with body aches and fever.
• Cough Suppressants: Using over-the-counter cough suppressants may be helpful if your cough is dry and prevents you from sleeping, but for a productive cough, it is often better to allow yourself to cough up the mucus. Honey can be an effective natural cough soother.
• Inhalers: If you are wheezing, your doctor may prescribe an inhaled bronchodilator (like albuterol) to help open up your airways.

How Chronic Bronchitis is Treated?

 There is no cure for chronic bronchitis as lung damage is permanent. The goals of treatment are to manage symptoms, reduce the frequency and severity of exacerbations (flare-ups), and improve quality of life.

• Smoking Cessation: This is the most important and effective intervention. Quitting smoking is the only thing that can slow down the progressive decline in lung function.
• Inhaled Medications:
  • Bronchodilators: These are the cornerstone of therapy. They are inhaled medications that relax the muscles around the airways, helping to open them up and make breathing easier.
  • Inhaled Corticosteroids: These may be added to a bronchodilator to reduce airway inflammation.
• Pulmonary Rehabilitation: This is a comprehensive program that includes exercise training, disease management education, and counseling to help improve physical fitness and quality of life.
• Oxygen Therapy: For patients with advanced disease and low blood oxygen levels.
• Vaccinations: It is essential for people with chronic bronchitis to get an annual flu vaccine and the pneumococcal vaccine to prevent infections that can cause severe exacerbations.

I’ve seen most cases improve with rest, hydration, and symptom relief, bronchodilators can help if wheezing is present, and antibiotics are rarely needed unless there’s a secondary infection.

Bronchitis is a term describing two very different conditions involving airway inflammation. Acute bronchitis is a common, self-limiting “chest cold,” almost always caused by a virus, that is best managed with rest, fluids, and patience as the lingering cough slowly resolves. For this condition, antibiotics are not the answer. In stark contrast, chronic bronchitis is a serious, lifelong lung disease, a form of COPD, caused by long-term damage to the airways, most often from cigarette smoke. Its management is a long-term partnership with a healthcare provider involving inhaled medications and, most importantly, smoking cessation. Understanding the crucial difference between these two types of “bronchitis” is the key to seeking the right care at the right time and protecting the health of your lungs.

Centers for Disease Control and Prevention (CDC). (2024). Chest Cold (Acute Bronchitis). Retrieved from https://www.cdc.gov/antibiotic-use/bronchitis.html

American Lung Association. (2023). Learn About Bronchitis. Retrieved from https://www.lung.org/lung-health-diseases/lung-disease-lookup/bronchitis

National Heart, Lung, and Blood Institute (NHLBI). (2023). COPD. Retrieved from https://www.nhlbi.nih.gov/health/copd