Understanding Phlegm: What Causes It to Accumulate and How to Reduce It Naturally

Phlegm, commonly referred to as mucus, is something most people only pay attention to when they’re sick, congested, or struggling with allergies. Yet mucus plays a vital role in protecting your respiratory system every day. It acts as a natural filter, trapping dust, allergens, viruses, and bacteria before they can reach the lungs. Under normal conditions, the body produces roughly 1 to 1.5 liters of mucus daily, and most of it is swallowed without you ever noticing (Cleveland Clinic, 2022).

Problems arise when mucus becomes too thick, excessive, or difficult to clear from the throat or chest. When that happens, knowing why it builds up — and how to reduce it safely — can make breathing easier and improve overall comfort.

What Is Phlegm, Exactly?

Phlegm is a thick, gel-like substance produced by the mucous membranes lining the throat, nasal passages, and lungs. It is made up of:

Water (its primary component)

Mucins, which give mucus its sticky texture

Immune cells such as neutrophils

Antibodies like IgA

Trapped particles including dust, allergens, and microbes

Mucus serves as the body’s first line of defense. It keeps airways moist and captures harmful substances. Tiny hair-like structures called cilia then move the mucus upward toward the throat, where it is either swallowed or expelled.

Why Does Phlegm Accumulate?

Several factors can increase mucus production or cause it to thicken, making it harder to clear.

1. Respiratory Infections

Colds, flu, bronchitis, and sinus infections activate the immune system, prompting extra mucus production to flush out pathogens. Viral infections usually cause clear or white mucus, while bacterial infections may produce yellow or green mucus due to immune cell activity (Mayo Clinic, 2023).

2. Allergies

Allergens such as pollen, dust mites, and pet dander trigger histamine release. This leads to swollen nasal passages and increased mucus production.

3. Smoking

Cigarette smoke irritates airway linings, damages cilia, and thickens mucus. This makes phlegm harder to clear and contributes to the chronic “smoker’s cough.”

4. Air Pollution and Irritants

Strong odors, chemical fumes, cleaning products, and polluted air can irritate the respiratory tract, causing the body to produce more mucus as a protective response.

5. Acid Reflux (GERD)

Stomach acid reaching the throat can irritate tissues, leading to a constant mucus sensation often described as postnasal drip.

6. Dry Air

Low humidity dries out airway tissues, prompting the body to produce extra mucus to compensate.

7. Chronic Respiratory Conditions

Conditions such as asthma, COPD, and chronic sinusitis are often associated with ongoing mucus production and congestion.

Natural Ways to Reduce Phlegm and Clear Airways

Before using medications, these evidence-supported home strategies may help manage mucus buildup.

1. Stay Well Hydrated

Drinking enough fluids helps thin mucus, making it easier to move and clear. Dehydration causes mucus to become thicker and stickier.

How it helps: Thinner mucus moves more efficiently along the cilia (American Lung Association, 2022).
Best options: Warm water, ginger tea, chamomile tea, clear broth
Limit: Excess caffeine and sugar, which may worsen dehydration

2. Gargle with Salt Water

Salt water can soothe irritated throat tissues and help draw out excess fluid through osmotic action.

How to use: Dissolve ½ teaspoon of salt in warm water and gargle two to three times a day.
Why it works: Salt helps reduce throat swelling and can temporarily limit bacterial growth (Journal of Clinical Medicine, 2020).

3. Steam Inhalation

Breathing warm, moist air can loosen mucus and relieve congestion.

How it helps: Steam increases moisture in the airways, reducing mucus thickness.
Optional: Add eucalyptus or peppermint oil
Limit sessions to 10 minutes and avoid burns

4. Warm Compresses

Placing a warm cloth on the chest or throat improves circulation, relaxes muscles, and helps loosen trapped mucus.

Why it helps: Heat softens secretions, making them easier to drain naturally.

5. Honey and Lemon

Honey offers antibacterial and anti-inflammatory properties, while lemon helps break down mucus due to its acidity and vitamin C.

Research: Honey has been shown to ease cough and throat irritation in both adults and children (BMJ Evidence-Based Medicine, 2018).
How to use: Mix one tablespoon of honey into warm water or tea with fresh lemon juice.

6. Use a Humidifier

Adding moisture to the air helps prevent dryness, which often contributes to thick mucus.

Best range: 40–50% humidity
Important: Clean humidifiers daily to prevent bacterial or mineral buildup.

7. Nasal Irrigation (Saline Rinse or Neti Pot)

Rinsing nasal passages helps remove irritants and improves drainage.

Evidence: Nasal irrigation can reduce congestion and improve symptoms of chronic sinusitis (International Forum of Allergy & Rhinology, 2017).
Use sterile or distilled water
Rinse once or twice daily during congestion

8. Reduce Exposure to Irritants

Common triggers that worsen mucus include:

Cigarette smoke

Strong fragrances

Polluted air

Household chemical fumes

Reducing exposure lowers inflammation and supports airway healing.

Foods and Habits That May Worsen Phlegm

To help limit mucus buildup, consider avoiding:

Smoking and secondhand smoke: A major contributor to chronic mucus production

Excess dairy (for some people): Dairy doesn’t increase mucus but can make it feel thicker (Harvard Health, 2022)

Sugary foods and drinks: Sugar may promote inflammation

Overuse of nasal sprays: Can cause rebound congestion if used too long

Suppressing coughs: Coughing helps clear mucus and shouldn’t be suppressed unless advised by a professional

When to Seek Medical Care

Consult a healthcare provider if:

Mucus lasts longer than three weeks

Mucus turns yellow, green, or bloody

You experience fever, chest pain, or breathing difficulty

Symptoms worsen despite home remedies

Persistent phlegm may indicate an underlying condition that requires treatment.

Final Thoughts

Phlegm is a normal and important part of your body’s defense system. However, when mucus becomes excessive, thick, or persistent, it can interfere with comfort and breathing. Staying hydrated, using steam, applying warmth, trying honey and lemon, and avoiding irritants can naturally reduce buildup and support respiratory health.

By understanding your personal triggers and knowing when symptoms need medical attention, you can manage phlegm more effectively and breathe easier day to day.