What causes excessive production of mucus (phlegm)?

From the Guidelines

Unnecessary production of phlegm is most commonly caused by chronic bronchitis, which is often associated with smoking and exposure to environmental pollutants, as stated in the 2020 Chest expert panel report 1.

Causes of Unnecessary Phlegm Production

The production of excess phlegm can result from various factors, including:

• Respiratory infections
• Allergies
• Asthma
• Chronic bronchitis
• COPD
• Environmental irritants According to the 2006 ACCP evidence-based clinical practice guidelines, cigarette smoking is responsible for 85 to 90% of cases of chronic bronchitis and COPD 1.

Management of Excess Phlegm

To manage excess phlegm, the following strategies can be employed:

• Stay well-hydrated with 8-10 glasses of water daily
• Use a humidifier
• Try saline nasal rinses
• Consider over-the-counter expectorants like guaifenesin (Mucinex) at 400-600mg every 12 hours to thin mucus
• Antihistamines such as loratadine (10mg daily) or cetirizine (10mg daily) can help if allergies are the cause
• Avoid smoking, limit dairy consumption, and minimize exposure to pollutants or allergens As noted in the 2006 ACCP evidence-based clinical practice guidelines, avoidance of environmental irritants is the most effective means for controlling cough and sputum production in patients with chronic bronchitis 1.

Importance of Medical Attention

If phlegm is discolored, accompanied by fever, persists beyond 10 days, or causes significant breathing problems, medical attention is necessary as it may indicate a more serious condition requiring prescription medications or further evaluation, as suggested by the 2006 ACCP evidence-based clinical practice guidelines 1.

From the FDA Drug Label

The viscosity of pulmonary mucous secretions depends on the concentrations of mucoprotein and, to a lesser extent, deoxyribonucleic acid (DNA). The causes of unnecessary production of phlegm are not directly addressed in the provided text, but it mentions that the viscosity of pulmonary mucous secretions depends on the concentrations of mucoprotein and deoxyribonucleic acid (DNA).

• Key points:
  • Mucoprotein and DNA contribute to the viscosity of pulmonary mucous secretions
  • The presence of cellular debris increases DNA, leading to increased viscosity However, the text does not provide a direct answer to the question of what causes unnecessary production of phlegm 2.

From the Research

Unnecessary Production of Phlegm Causes

• The production of excess phlegm can be caused by various factors, including respiratory diseases such as chronic obstructive pulmonary disease (COPD) 3.
• In COPD, the mucus clearance system is disrupted, leading to the accumulation of mucus in the airways, which can cause symptoms such as coughing and wheezing 3.
• The pathogenesis of muco-obstructive lung diseases, including COPD, involves the derangement of ion transport pathways that normally hydrate mucus, leading to the formation of adherent mucus plaques and plugs 3.
• These mucus plaques can create locally hypoxic conditions, produce airflow obstruction, inflammation, infection, and ultimately, airway wall damage 3.
• The use of inhaled corticosteroids (ICS) combined with long-acting bronchodilators, such as long-acting β2-adrenoreceptor agonists (LABA) and long-acting muscarinic antagonists (LAMA), is recommended for symptom control and exacerbation reduction in COPD patients 4.
• However, the effect of ICS-containing therapies on mortality in COPD patients remains uncertain, although recent studies suggest potential mortality benefits with triple ICS/LABA/LAMA therapy 4.

Related Conditions

• COPD exacerbations are a hallmark feature of the disease and contribute to morbidity and mortality 5, 6.
• The treatment of COPD exacerbations typically involves the use of bronchodilators, corticosteroids, and antibiotics, although the best drug selection, dose, route, and duration of treatment remain uncertain 5, 6.
• The management of COPD also involves the use of inhaled long-acting bronchodilators, inhaled corticosteroids, and their combinations for maintenance treatment of moderate to severe COPD 7.