Are you worried about coughing up mucus? Well, it is nothing to be afraid of, much less to let fear get the best of you. 

Coughing up mucus is the body's natural response to irritation or infection in the respiratory system. It can be a normal and healthy response to respiratory irritation, such as exposure to pollutants or allergens.

But what is mucus? Mucus is a sticky, gel-like substance produced by the lining of the respiratory tract; it helps to protect and moisturize the airways, trap and clear foreign particles, and fight infections. It is also produced in other parts of the body, including the GI tract (stomach and colon), eyes, and inner ear.

Mucus Composition

• Water
• Antibodies
• Enzymes
• Proteins 
• Salt

It may also entrap:

• Dead cells
• Dust 
• Debris

Interestingly there are reasons why mucus happens in the respiratory system. Studies¹ suggest that functions of respiratory mucus include keeping the respiratory tract hydrated and serving as a barrier against the outside environment by trapping particulates, including infections.

It also has other functions such as:

• It facilitates the movement of cilia (tiny hair-like structures) that help move the mucus and trapped particles out of the respiratory system
• It helps flush out the irritants and reduce inflammation during occurrence of respiratory infections or allergies.

Let's dig deeper into what the color or texture of your mucus specifies. Keep in mind your doctor will go for a sputum test to conclude. 

1. Frothy White Mucus

Mucus with air bubbles or a foamy appearance is usually normal. However, if your mucus shows a slight pink or light reddish shade, it might be a sign of chronic illness such as:

• Acid reflux
• Chronic Obstructive Pulmonary Disease
• Pulmonary edema
• Issues with the heart

So what does white mucus mean? White phlegm or opaque phlegm without much color is a symptom of allergies, asthma, and frequently, viral infections. The presence of more white blood cells trying to fight infection accounts for the color.

There are different types of white mucus, including frothy white sputum, which can also appear cloudy, and thick white mucus. White frothy or foamy mucus could be a sign of excess saliva or a respiratory infection, while cloudy white mucus is typically normal. Thick white mucus and congestion could be early signs of a sinus infection or allergies.  If you have asthma ², having a lot of white phlegm may indicate that your airways are inflamed.

This research article states: Cough and Sputum Production Are Associated With Frequent Exacerbations and Hospitalizations in COPD Subjects.

2. Thick or Solid White Mucus

Dehydration and swollen tissues are the reason behind thick white mucus. Using a humidifier and increase in water intake aids in recovering this problem.

Secondly, thick phlegm can also represent bacterial infection of your airways. Thus, it is essential to visit your doctor to start antibiotic treatment. 

Mainly asthma, viral inflammation, and allergies can turn your sputum white. Taking anti-allergies, anti-histamines, and nasal drops can work if an allergy is an underlying root. 

3. Clear Mucus

This type of transparent or colorless mucus is typically normal and is produced in the respiratory tract to help keep it moist and to trap any foreign particles that may enter. If you're coughing up clear phlegm with bubbles or light-colored mucus, it could signify a mild infection in your respiratory system or allergies.

4. Black/Charcoal/Gray Mucus

Charcoal or gray phlegm typically appears in people who work in chemical or charcoal manufacturing factories, coal mines, and smokers. 

In addition, factory workers or coal miners who do not adhere to safety precautions and use facemasks are more prone to black phlegm.

The medical term for black sputum is melanoptysis. The appearance of black phlegm could indicate that you have inhaled a significant amount of black particles or have an infection 

Studies suggest³ that black, black-gray, or charcoal colored mucus can be caused by:

• Fungal infection⁴
• Exposure to air pollution, dust or smoking, and/or damage to the respiratory tract from these.
  • One study found that coal miners⁵, along with those working in construction and other industries involving exposure to airborne particles had an increased risk of developing black lung disease, which can cause coughing and the production of black phlegm. It is considered an occupational hazard. Other lung conditions caused by coal mine dust (CMDLD) include chronic obstructive pulmonary disease (COPD), coal workers' pneumoconiosis, silicosis, mixed dust pneumoconiosis, and  dust-related diffuse fibrosis.
• Smoking – This can cause black mucus due to tar and other chemicals in cigarette smoke that can build up in the respiratory system and lead to inflammation and excess mucus production

Rarely, black phlegm can be a symptom of a more serious condition, such as lung cancer⁶ or tuberculosis, if present with symptoms, such as coughing up blood, chest pain, or shortness of breath.

5. Yellow/Green Mucus

Purulent is the other name given to this type of phlegm. As it contains ‘pus’. This color appears when neutrophils (a type of white blood cells) accompany the sputum. 

Yellow mucus is typically produced when the body is fighting an infection such as cold, flu, or sinusitis. It can indicate that the body is producing white blood cells to combat the infection, which can cause the mucus to become thick and discolored.

Although phlegm of this color may indicate an illness, medications are not always necessary. Most viral infections that result in green phlegm normally go away on their own in weeks. Antibiotics do not help with viral infections like the common cold.

Oftentimes, after a few days, the phlegm turns back white⁷. If this doesn't happen for an extended period of time, it can be a sign of a more serious viral/bacterial infection such as:

• Sinusitis – Also known as sinus inflammation 
• Bronchitis – While the cough associated with this airway issue normally begins out dry, it can develop into one that produces clear or white phlegm as it progresses. If an infection is present, it may also generate green phlegm (which may move from viral to bacterial in nature)
• Pneumonia– This disease comes in bacterial, fungal, and viral varieties, frequently developing from an earlier respiratory infection
• Cystic fibrosis – The accumulation of mucus in the lungs is a central trait of this chronic respiratory illness. Cystic fibrosis phlegm can range in hue from light yellow to dark green.

Before using antibiotics, one should speak with their doctor. Inappropriate use of antibiotics can lead to bacterial resistance, which is harmful.

6. Pink or Red Mucus

Frothy pink sputum, or even red, can indicate the presence of bleeding in the respiratory system. When you cough up blood, it frequently appears bubbly or frothy and is combined with mucus or spit. It often exists in minute concentrations and might seem pink, crimson, or rust-colored.

Blood-tinged sputum⁸ an signify a more serious underlying condition, such as:

• Respiratory infections – Infections of the respiratory system, such as bronchitis or pneumonia, can irritate and inflame the respiratory system, causing it to bleed slightly, leading to red or pink mucus.
• Pulmonary edema⁹ – A sign of pulmonary edema is foamy pink sputum and shortness of breath; blood and fluid flow into the lungs from the alveoli. Consult a doctor as quickly as possible to rule out congestive heart failure, whose frequent symptom is pulmonary edema.
• Trauma to the respiratory system – A punctured lung or a fractured rib can cause bleeding in the respiratory system, leading to the production of red or pink mucus.
• Lung cancer – This can cause bleeding in the respiratory system, leading to the production of red or pink mucus

You should see your doctor if you're producing phlegm that is red, pink, or bloody. It is alarming if you smoke and you are coughing up blood. Before reaching a diagnosis, your doctor may request a chest x-ray and conduct a more thorough health exam.

7. Brown Mucus

Your mucus turns brown due to persistent inflammation causing upper respiratory tract damage, which combines mucus with debris, old blood, tar that has loosened up after you've stopped smoking, or a combination of all three. Lung inflammation also causes a generalized increase in mucus production, which can result in a persistent cough.

The following medical issues are connected to the emergence of brown mucus or phlegm:

• Black lung (coal miners' lung or pneumoconiosis in coal workers)
• Lung fungal diseases, like aspergillosis
• Lung cancer
• Lung abscess¹⁰
• Pneumococcal pneumonia¹¹
• Lung injury brought on by breathing in smoke from a house or fire

Frequently Asked Questions

When Should I See My Healthcare Provider?

When should I be concerned about coughing up mucus? If you are experiencing excessive mucus production or have other concerns about your health, it's always best to consult with a healthcare professional for personalized advice and treatment. Additionally, you should see your healthcare provider if you experience the following:

• Coughing up large amounts of mucus
• If the mucus is thick and difficult to cough up
• Coughing up blood or pink, frothy mucus
• Chest pain or discomfort
• Shortness of breath or wheezing
• A fever of 100.4°F (38°C) or higher
• A persistent cough that lasts for more than two weeks
• Difficulty swallowing
• Loss of appetite or unintentional weight loss.
• Chronic lung conditions such as asthma, COPD, or cystic fibrosis that worsen
• A cough that disrupts your sleep or daily activities.

It's important to seek medical attention if you are experiencing any of these symptoms, as they could be signs of a more serious underlying condition that requires treatment. Your healthcare provider can diagnose the cause of your symptoms and recommend the appropriate treatment.

Conclusion

Coughing up mucus is a common symptom associated with various respiratory illnesses. Most importantly, the mucus's color and texture help you know if you should be concerned. Whether clear, discolored, thick, or persistent may indicate an underlying infection or inflammation, making medical evaluation and treatment potentially necessary.

. 

• U.S. adults' knowledge of various infectious diseases by age 2017 

• Top respiratory products by revenue U.S. 2016 

Reference

• Mucus and Phlegm: Barometers of Your Health 
• Coughing Up White Mucus: Causes and Treatment (healthline.com)
• Coughing up white mucus: Causes and treatments (medicalnewstoday.com)
• Mucus in Your Chest: See 8 Different Causes (And How to Remedy It) (webmd.com)
• Reasons You're Coughing Up White Mucus (verywellhealth.com)
• What Is Mucus? Learn How to G

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Marion Sereti

Marion is a freelance health and wellness writer with a passion for all things digital health. She loves diving deep into the latest research and trends in the industry and distilling them down into fun, relatable pieces that people can relate to. Whether you're a health nut or a tech geek, she is always looking for new and interesting ways to help readers access quality and evidence-based information.