Main reasons for phlegm
Infections:
Viral infections: When you have a viral infection like the common cold or flu, your body produces more phlegm.
Bacterial infections: Sinusitis, bronchitis, and pneumonia are the main causes of phlegm.
Allergies: When you are allergic to dust, pollen, pet dander, and certain foods, your body’s mucus membranes produce more phlegm.
Smoking: The chemicals in tobacco irritate the lungs and airways and increase the amount of phlegm.
Air pollution: When dust, smoke, and chemicals in the air enter the lungs, the body produces phlegm to expel it.
Asthma: People with asthma tend to have more phlegm due to inflammation in the airways.
Gastroesophageal reflux disease (GERD): When stomach acid flows back up into the throat (heartburn), it can feel like mucus is stuck in the throat.
Dry weather: When the humidity in the air is low, the airways dry out, and the body produces more mucus to protect it.
