OVERVIEW

What is chronic bronchitis?

Chronic bronchitis, abbreviated as "chronic bronchitis," is a chronic nonspecific inflammation of the trachea, bronchial mucosa, and surrounding tissues.

Clinically, it is characterized by cough and sputum production as the main symptoms, sometimes accompanied by wheezing. The condition persists for 3 months or longer each year, for 2 consecutive years or more, while excluding other diseases with similar symptoms. It is a common chronic illness caused by factors such as smoking and environmental influences.

If patients with chronic bronchitis actively cooperate with treatment and take preventive measures, the condition can be controlled. Without effective treatment and management, chronic bronchitis may progress to chronic obstructive pulmonary disease (COPD) or even cor pulmonale.

Is chronic bronchitis common?

Yes, it is common. According to recent census data in China, the prevalence of chronic bronchitis ranges from 2.5% to 9.0%, with an average of 4.0%. The prevalence increases with age, exceeding 15% in individuals aged 50 and above.

Is chronic bronchitis the same as "old chronic bronchitis"?

"Old chronic bronchitis" is a colloquial term for "chronic bronchitis in the elderly." A significant proportion of chronic bronchitis patients are aged 50 or older. These patients often experience symptoms such as cough, excessive sputum, wheezing, and chest tightness. Compared to younger patients, elderly patients exhibit more pronounced symptoms, longer disease duration, and frequent recurrences, severely affecting their quality of life.

Which department should chronic bronchitis patients visit?

Respiratory Medicine.

SYMPTOMS

What are the common manifestations of chronic bronchitis?

The disease progresses slowly with recurrent episodes, characterized by coughing, sputum production, or accompanied by wheezing. Acute exacerbations refer to the worsening of these symptoms, often caused by respiratory infections.

• Cough: In the early stages, it is mainly dry cough, occurring more during the day than at night. As the condition progresses, sputum production increases, the cough becomes heavier and more persistent, often presenting as paroxysmal coughing, particularly noticeable before bedtime or upon waking up in the morning.

• Sputum production: Most patients produce large amounts of white, sticky sputum, with increased frequency in the morning and at night. During exacerbations or infections, the sputum becomes thicker and yellow. Elderly individuals may have difficulty expectorating due to weakened cough reflexes.

• Wheezing: Seen in patients with the wheezing type, it becomes more pronounced after infections or exertion. Shortness of breath and wheezing worsen if emphysema (a pathological condition of lung overinflation due to lung disease) develops.

Additionally, doctors may use a stethoscope for diagnosis. In the early stages of chronic bronchitis, there are no obvious physical signs. During acute exacerbations, dry or wet rales may be heard on lung auscultation, which may decrease or disappear after coughing.

What is the relationship between chronic bronchitis, emphysema, chronic obstructive pulmonary disease (COPD), and cor pulmonale?

Chronic bronchitis is defined as a condition where a patient coughs for more than three months per year for at least two consecutive years, after excluding other known causes of chronic cough. Emphysema refers to abnormal, persistent dilation of the air spaces distal to the terminal bronchioles, accompanied by destruction of alveolar walls and bronchioles without significant pulmonary fibrosis.

When patients with chronic bronchitis or emphysema show persistent airflow limitation in pulmonary function tests, they can be diagnosed with COPD. If patients only have chronic bronchitis and/or emphysema without persistent airflow limitation, they cannot be diagnosed with COPD.

Cor pulmonale, or pulmonary heart disease, refers to structural or functional changes in the right ventricle caused by increased pulmonary vascular resistance due to bronchopulmonary, thoracic, or pulmonary vascular diseases. It can be classified as acute or chronic based on onset and duration. Acute cor pulmonale is commonly caused by acute massive pulmonary embolism. Chronic cor pulmonale often results from chronic bronchopulmonary diseases, especially COPD, accounting for about 80–90% of cases.

What serious consequences can chronic bronchitis cause?

If chronic bronchitis is not effectively treated and controlled, it may progress to COPD or even cor pulmonale.

Is chronic bronchitis life-threatening?

Chronic bronchitis alone is not life-threatening. However, during acute exacerbations with bacterial, viral, or mycoplasma infections, failure to control the infection promptly and effectively can be life-threatening.

Additionally, if patients do not receive active treatment or fail to manage disease progression, leading to COPD or cor pulmonale, it may also become life-threatening.

CAUSES

What are the common causes of chronic bronchitis?

• Smoking: Smoking is the most significant environmental risk factor. The incidence of chronic bronchitis in smokers is 2-8 times higher than in non-smokers.

• Occupational dust and chemicals: Exposure to occupational dust and chemicals, such as smoke, industrial exhaust, and indoor pollution, can contribute to the development of chronic bronchitis if the concentration is too high or the exposure is prolonged.

• Air pollution: Harmful gases in the atmosphere, such as sulfur dioxide, nitrogen dioxide, and chlorine, can damage the airway mucosal epithelium, impair ciliary clearance, increase mucus secretion, and raise the risk of bacterial infections.

• Infectious factors: Infections caused by viruses, mycoplasma, and bacteria are important contributors to the onset and progression of chronic bronchitis.

• Other factors: Immune dysfunction, airway hyperresponsiveness, and aging are also associated with the development and progression of chronic bronchitis.

Can smog cause chronic bronchitis?

Yes.

Sulfur dioxide, carbon oxides, and inhalable particulate matter are the main components of smog. The first two are gaseous pollutants, while particulate matter is the primary culprit behind smog pollution. Among inhalable particles, those with a diameter of 2.5 μm or smaller are called PM2.5, also known as fine particulate matter. PM2.5, or respirable particulate matter, can carry large amounts of toxic and harmful substances, damage the airway mucosal epithelium, impair ciliary clearance, and increase mucus secretion, thereby triggering chronic bronchitis and raising the risk of bacterial infections.

Who is more likely to develop chronic bronchitis?

Elderly individuals are more susceptible to chronic bronchitis, especially smokers.

Can chronic bronchitis occur in children or young adults?

Yes. However, the prevalence is lower compared to the elderly.

Is chronic bronchitis contagious?

No.

Chronic bronchitis itself is not contagious. However, during acute exacerbations, it is often accompanied by bacterial, viral, or mycoplasma infections, which can be contagious. To prevent transmission, it is advisable to wear a mask when in contact with patients.

DIAGNOSIS

What tests are needed for chronic bronchitis?

• Chest X-ray: Early stages usually show no abnormalities. As the condition progresses, recurrent episodes may manifest as thickened, disordered lung markings, appearing as网状,条索状, or斑点状 shadows, particularly in the lower lung fields.

• Pulmonary function tests: Early stages may show no abnormalities. The ratio of forced expiratory volume in one second (FEV₁) to forced vital capacity (FVC) is measured after using a bronchodilator. If FEV₁/FVC < 0.70, it suggests progression to chronic obstructive pulmonary disease (COPD).

• Blood tests: During bacterial infections, total white blood cell count and/or neutrophil levels may increase. No abnormalities are typically seen in non-acute phases.

• Sputum examination: Pathogenic bacteria may be cultured, or large numbers of destroyed white blood cells and goblet cells may be observed.

Why are chest X-rays, pulmonary function tests, blood tests, and sputum examinations performed for chronic bronchitis? What precautions should be taken for these tests?

• Chest X-ray: The purpose is to observe lung lesions from an imaging perspective. Precautions include removing metal clothing and accessories from the patient's chest to avoid artifacts. The patient should hold a deep breath and remain still during imaging to ensure full lung expansion.

• Pulmonary function tests: The purpose is to assess lung function and differentiate diagnoses such as COPD or asthma. Precautions include:

• Patients should rest quietly for 15 minutes before testing.

• Patients with high fever, severe cough, or extreme weakness should postpone testing.

• Patients with肺大泡, spontaneous pneumothorax, or recent咳血 (must wait two weeks after bleeding stops) should avoid testing.

• Patients with infectious diseases should postpone testing.

• Blood tests: The purpose is to determine whether bacterial, viral, or mycoplasma infections are present.

• Sputum examination: The purpose is to culture pathogenic bacteria and conduct drug sensitivity tests to select the best antibiotics. Precautions include rinsing the mouth with sterile water to avoid contamination by normal oral bacteria. Morning deep sputum samples are preferred for testing.

Which diseases are easily confused with chronic bronchitis?

• Bronchial asthma: Some asthma patients present with刺激性咳嗽, often starting in childhood. Triggers like油烟 or cold air are common, and there is often a family or personal history of allergies. Antibiotics are ineffective, symptoms appear and disappear suddenly, and解痉药 provide relief. Symptoms are usually absent during intervals, and bronchial provocation tests are positive.

• Tuberculosis: Fever is the most common symptom, often午后潮热 (rising in the afternoon or evening). Some patients experience fatigue, night sweats, loss of appetite, and weight loss. Sputum tests for acid-fast bacilli and chest X-rays can differentiate.

• Bronchiectasis: More common in children and young adults, characterized by chronic cough, recurrent大量咯脓痰, or咯血. Chest X-rays and high-resolution螺旋 CT scans can aid diagnosis.

• Pneumoconiosis: Patients may exhibit咳嗽,咳痰, or喘息, which are not specific to pneumoconiosis. Early stages often show no obvious symptoms, while later stages may include chest tightness, shortness of breath, and fatigue due to hypoxia. Diagnosis relies on dust exposure history and chest X-rays.

How to differentiate between chronic bronchitis and chronic pharyngitis?

Chronic pharyngitis: A chronic inflammation of the咽部黏膜 and submucosal tissues, presenting with咽痛,咽痒, dry cough,异物感, and worsening with excessive talking. Viruses and bacteria are the main pathogens.
Chronic bronchitis: Primarily involves咳嗽,咳痰, and/or喘息, lasting ≥3 months per year for ≥2 consecutive years, after excluding other diseases with similar symptoms.

Different clinical presentations and medical histories help distinguish the two.

TREATMENT

How to treat chronic bronchitis?

Most common treatments for chronic bronchitis focus on prevention first, followed by management.

Adopt a positive and healthy lifestyle and habits:

• Quit smoking and avoid inhaling harmful gases and other toxic particles.
• Maintain personal hygiene and a balanced diet, opting for light meals and reducing salt intake.
• Engage in regular exercise to strengthen immunity and prevent recurrence of chronic bronchitis.
• Prevent colds, as they are a major trigger for chronic bronchitis.

During acute episodes or chronic persistent phases:

• Undergo antibacterial treatment to control infection progression. Commonly used medications include amoxicillin and cefalexin. For severe infections, drugs like ofloxacin or ampicillin may be prescribed.
• Receive expectorant and antitussive therapy. Medications such as biclotymol are often used. For patients with wheezing, bronchodilators like aminophylline or procaterol may be administered. Treatment varies by hospital and should be tailored to the patient’s specific symptoms.

What are the common side effects of chronic bronchitis medications?

• Levofloxacin commonly causes gastrointestinal reactions like abdominal discomfort, pain, diarrhea, nausea, or vomiting. Some patients may also experience central nervous system effects such as dizziness, headache, drowsiness, or insomnia.
• Compound licorice mixture may cause mild nausea or vomiting.
• Bromhexine may lead to nausea, stomach discomfort, or elevated liver enzymes. It should be used cautiously in patients with gastric ulcers.

Does chronic bronchitis require regular follow-ups? How are follow-ups conducted?

Yes. During acute exacerbations, follow-ups may include chest X-rays, blood tests, sputum examinations, and lung function tests. During remission, lung function tests are recommended.

Can chronic bronchitis be cured?

Chronic bronchitis is generally considered incurable because long-term recurrent inflammation causes permanent airway damage.

However, proactive management can control symptoms and improve quality of life.

Management strategies include:

• Quitting smoking and avoiding smoke, air pollution, and other respiratory irritants.
• Medications: Bronchodilators, inhaled corticosteroids, etc. Use inhalers correctly under medical guidance.
• Pulmonary rehabilitation: Includes appropriate exercise and nutritional guidance.
• Healthy lifestyle: Balanced diet, regular exercise, and maintaining good air quality.
• Infection prevention: Annual flu and pneumonia vaccines, hand hygiene, wearing masks in high-risk settings, and prompt treatment of respiratory infections.
• Regular monitoring: Lung function tests every 3 months to 1 year, depending on disease severity^[1].

How to prevent acute exacerbations of chronic bronchitis?

Quit smoking, avoid harmful gases and particles, strengthen immunity, and prevent colds.

DIET & LIFESTYLE

What should chronic bronchitis patients pay attention to in their diet?

During acute exacerbation of chronic bronchitis:

• Encourage consumption of easily digestible foods high in calories and protein;
• Avoid strongly irritating or spicy foods;
• Eat smaller, more frequent meals, opting for soft, easy-to-swallow foods. Drink plenty of water to promote metabolism, help dilute phlegm, and make it easier to expel.

During remission of chronic bronchitis:

• Eat more fresh fruits and vegetables;
• Maintain a balanced diet with meat and vegetables, using less salt and high-sodium seasonings during cooking;
• Limit intake of pickled vegetables and meats;
• Avoid alcohol and drink plenty of water. In addition to diet, engage in about 30 minutes of daily exercise, combining aerobic and strength training at moderate intensity. Ensure adequate sleep and learn to manage stress and tension.

What should chronic bronchitis patients pay attention to in daily life?

• Quit smoking and avoid inhaling harmful gases or particles. Wear a mask in dusty environments;
• Maintain a regular sleep schedule and get enough rest;
• Learn to manage stress and emotional tension;
• Engage in about 30 minutes of daily exercise, combining aerobic and strength training at moderate intensity;
• Strengthen immunity to prevent colds.

When should chronic bronchitis patients seek medical attention promptly?

Seek medical attention if any of the following occurs:

• Persistent cough lasting more than 3 weeks;
• Severe cough that disrupts sleep;
• Thick yellow phlegm;
• Coughing up blood or blood-streaked phlegm;
• Fever with a temperature above 38°C;
• Chest tightness, shortness of breath, or difficulty breathing.

Can chronic bronchitis patients fly, engage in intense exercise, or travel to high-altitude areas?

Once the condition is under control, daily activities like work or study are generally unaffected. Patients can fly but should avoid intense exercise. Light aerobic activities like walking or tai chi are recommended. Travel to high-altitude areas is generally not advised.

How to care for chronic bronchitis patients?

• Supervise the patient to quit smoking;
• Avoid exposure to harmful gases or particles;
• Keep warm to prevent colds;
• Ventilate the room regularly to maintain a clean and comfortable environment;
• If coughing, phlegm, or wheezing occurs, help the patient assume a semi-reclined position and gently pat their back;
• Seek immediate medical attention if symptoms worsen.

PREVENTION

Can Chronic Bronchitis Be Prevented? How to Prevent Chronic Bronchitis?

Yes, it can be prevented. The prevention principles are:

• Quit smoking and avoid inhaling harmful gases and other hazardous particles;

• Strengthen physical fitness, dress appropriately, and prevent colds;

• For patients with weakened immunity, use immunomodulators under medical guidance. Additionally, vaccinations such as flu and pneumonia vaccines can be administered.