Phlegm—often simply called mucus—is something most people notice only when they’re sick, congested, or dealing with allergies. But mucus plays an essential role in protecting your respiratory system every single day. It traps dust, allergens, viruses, and bacteria before they reach your lungs. Under normal circumstances, your body produces 1 to 1.5 liters of mucus daily, most of which you swallow without realizing it ( Cleveland Clinic, 2022).

However, certain conditions can cause your mucus to thicken, become excessive, or feel stuck in your throat and chest. When this happens, understanding the causes and knowing how to reduce buildup can greatly improve your comfort and breathing.

What Exactly Is Phlegm?

Phlegm is a gel-like secretion produced by the mucous membranes of the throat, nasal passages, and lungs. It contains:

• Water (the main component)
• Mucins (proteins that give mucus its sticky consistency)
• Immune cells, such as neutrophils
• Antibodies, like IgA
• Trapped particles such as dust, allergens, microbes

The body uses mucus as a first line of defense. It moisturizes the airways and traps harmful particles, while tiny hair-like structures called cilia sweep the mucus upward toward the throat, where it is swallowed or expelled.

Why Does Phlegm Build Up?

Several factors can increase mucus production or thicken the mucus so that it becomes harder to clear.

1. Respiratory Infections

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

2. Allergies

Allergens such as pollen, pet dander, and dust mites can trigger the release of histamine, leading to swelling of the nasal passages and excess mucus production.

3. Smoking

Cigarette smoke irritates the airways, paralyzes cilia, and thickens mucus. This makes it difficult for the lungs to clear phlegm, contributing to the well-known “smoker’s cough.”

4. Air Pollution & Irritants

Strong perfumes, cleaning chemicals, and polluted air can irritate the respiratory lining and cause increased mucus as a protective response.

5. Gastroesophageal Reflux (GERD)

Acid reflux can irritate the throat and lead to chronic mucus sensation or “postnasal drip.”

6. Dry Air

Low humidity dries out the airway tissues, causing the body to overproduce mucus to compensate.

7. Chronic Respiratory Conditions

Asthma, COPD, and chronic sinusitis can all lead to persistent mucus production and congestion.

Natural Remedies to Reduce Phlegm and Clear Your Airways

Before turning to medication, the following science-backed home remedies may help reduce mucus buildup.

1. Stay Hydrated

Drinking water, herbal teas, or warm broths helps thin mucus. When you are dehydrated, mucus becomes thicker, stickier, and harder to clear.

How it works: Thin mucus moves more easily along the cilia, improving clearance (American Lung Association, 2022).

• Best choices: warm water, ginger tea, chamomile tea, broth
• Avoid: excessive caffeine and sugar, which can worsen dehydration

2. Gargle with Salt Water

Salt water can soothe irritated throat tissues and draw out excess fluid due to its natural osmotic effect.

How to do it: Mix ½ teaspoon of salt in a warm glass of water and gargle 2–3 times daily.

Scientific note: Salt reduces swelling in the throat and can temporarily neutralize bacteria (Journal of Clinical Medicine, 2020).

3. Use Steam Inhalation

Warm, moist air loosens mucus and helps relieve congestion.

How it helps: Steam increases airway moisture, reducing mucus thickness and easing its movement.

• Add eucalyptus or peppermint oil (optional)
• Limit to 10 minutes and avoid burns

4. Apply a Warm Compress

A warm cloth placed on the chest or throat improves blood flow, relaxes chest muscles, and helps loosen stuck mucus.

Why it works: Heat softens secretions, aiding in natural drainage.

5. Honey and Lemon

Honey has antibacterial and anti-inflammatory properties, while lemon breaks down mucus due to its natural acidity and vitamin C content.

Research: Honey has been shown to reduce cough frequency and soothe irritation in children and adults (BMJ Evidence-Based Medicine, 2018).

How to use: Mix 1 tablespoon of honey with warm water or tea and a squeeze of lemon.

6. Use a Humidifier

Increasing humidity in your environment helps prevent dryness, which often triggers thick mucus.

Tip: Keep humidity around 40–50%; too much can promote mold growth.

Important: Clean your humidifier daily to prevent bacteria and mineral buildup.

7. Try Nasal Irrigation (Neti Pot or Saline Rinse)

Rinsing your nasal passages can dramatically reduce congestion and remove irritants.

Evidence: Studies show nasal irrigation improves sinus drainage and reduces symptoms of chronic sinusitis (International Forum of Allergy & Rhinology, 2017).

• Use sterile or distilled water to avoid infection risk
• Rinse once or twice daily during congestion

8. Avoid Irritants

Common irritants that worsen mucus include:

• Cigarette smoke
• Strong fragrances
• Air pollution
• Household chemical fumes

Limiting exposure reduces inflammation and allows your respiratory system to heal.

Foods and Habits That May Worsen Phlegm

To help reduce mucus buildup, avoid:

• Smoking & Secondhand Smoke

A major trigger for chronic mucus production and respiratory illness.

• Excess Dairy (for some people)

While dairy doesn’t increase mucus production, it can make mucus feel thicker due to its creamy texture (Harvard Health, 2022).

• Sugary Foods & Drinks

Sugar can promote inflammation and worsen throat irritation.

• Overusing  Nasal Sprays

Decongestant sprays can create dependence and worsen congestion if used longer than recommended.

• Suppressing Cough Reflex

Coughing is your body’s natural way of clearing mucus—don’t suppress it unless medically advised.

When Should You See a Doctor?

Seek medical attention if:

• Mucus lasts longer than 3 weeks
• Mucus becomes yellow, green, or bloody
• You have fever, chest pain, or difficulty breathing
• Symptoms worsen despite home care

Chronic phlegm may signal an underlying condition requiring treatment.

Conclusion

Phlegm is a natural and essential part of your body’s defense system. However, when mucus becomes excessive, thick, or persistent, it can interfere with breathing and daily comfort. By staying hydrated, using steam, applying warm compresses, trying honey and lemon, and avoiding irritants, you can naturally reduce mucus buildup and support respiratory health.

Understanding your triggers—and paying attention to when symptoms don’t improve—will help you manage phlegm effectively and know when to seek medical care.