What Causes Phlegm?

Phlegm is a thick, viscous mucus that is produced by the respiratory system. It serves several important functions, including trapping and removing foreign particles, such as dust and microbes, from the airways, and helping to keep the airways moist. Phlegm production can be a normal and healthy response to various factors, but it can also be a sign of an underlying issue. Some common causes of increased phlegm production include:

  • Respiratory Infections: Infections such as the common cold, flu, bronchitis, and pneumonia can stimulate the body to produce more phlegm as a defense mechanism to trap and remove pathogens from the respiratory tract.
  • Allergies: Allergic reactions to airborne allergens, like pollen, dust mites, animal dander, or mold, can lead to increased mucus production as the body tries to flush out the allergens.
  • Irritants: Exposure to irritants like cigarette smoke, air pollution, chemical fumes, or strong odors can stimulate the production of phlegm in an attempt to protect the respiratory tract from potential harm.
  • Gastroesophageal Reflux Disease (GERD): GERD is a condition where stomach acid flows back into the esophagus, which can irritate the throat and lead to increased mucus production.
  • Postnasal Drip: Excessive mucus can drip down the back of the throat from the nasal passages, leading to phlegm in the throat. This can occur due to allergies, sinus infections, or other nasal conditions.
  • Asthma: Inflammation and narrowing of the airways in asthma can result in increased mucus production and difficulty clearing it from the airways.
  • Environmental Factors: Cold and dry weather, as well as low humidity levels, can contribute to thicker mucus production.
  • Medications: Some medications, especially those with anticholinergic properties, can dry out the mucous membranes, leading to reduced mucus production and potentially thicker phlegm.
  • Dehydration: Inadequate fluid intake can lead to thicker mucus and make it more difficult to clear from the respiratory tract.
  • Infections Beyond the Respiratory System: Certain systemic infections or infections in other parts of the body can lead to increased phlegm production as a secondary symptom.

If you are experiencing persistent or bothersome phlegm production, especially if it is accompanied by other symptoms like fever, coughing, or difficulty breathing, it’s important to consult a healthcare provider. They can determine the underlying cause of your phlegm and recommend appropriate treatment or management strategies, which may include medications, lifestyle changes, or addressing the underlying condition.