Coughing Up Brown or Black Mucus: What It Means According to Science

Coughing Up Brown or Black Mucus: What It Means

Coughing up brown or black mucus is never a pleasant experience. The color of coughed up mucus can tell a lot about your health, especially if it is rusty-colored or black. Usually, black mucus (medical name melanoptysis) is a symptom of irritation or an infection in the lungs. However, there is also a chance that brown or rusty colored mucus is tinged with old blood that is being coughed up with your phlegm. Depending on what is causing the dark-colored mucus in your cough, there could be nothing to worry about or you may need to see a doctor to get the cause of the black mucus checked out.

Mucus in your airways is essential to protect your lungs from irritants and fight off infections. Mucus traps dust particles, smoke, and bacteria. If irritation or an infection affects your lungs, you need to cough to bring up phlegm to help keep your lungs clear. Smoke, dust, or bacterial infections can turn mucus black. Mucus that has blood in it may have a rusty-brown appearance.

Mucus that is expelled by coughing is also referred to as sputum – a thick, sticky substance that is coughed up from the lungs. Doctors may even send a sample of sputum for analysis to check for the presence of brown spots or black bits in the mucus.

In this article, I will examine what scientific research reveals as to the causes of brown, rusty, or black mucus. You will also learn how to treat symptoms of coughing up brown mucus or black mucus. Very often, natural remedies to clear your lungs can help to treat respiratory infections and get rid of abnormal-colored phlegm.

Symptoms Related to Brown, Black, or Rusty Sputum

Coughing up brown mucus is usually associated with other symptoms of a lung infection or irritated airways. Coughing can be very frustrating because it can make breathing difficult and make you feel uncomfortable. A “productive” cough will forcefully expel sputum from your airways.

Some accompanying symptoms of bringing up black, brown or rusty sputum can include:

  • A deep hacky cough that brings up dark phlegm
  • Symptoms of irritation in the airways like a sore throat or sore chest
  • Wheezing and/or shortness of breath
  • Signs of a respiratory infection like blocked sinuses, a fever, a runny nose, or a sore throat
  • Difficulty swallowing
  • Heartburn

Coughing Up Black Mucus: Common Causes

Coughing up green phlegm is usually associated with a cold, so, what can it mean if your notice that your cough produces mucus that is black or has black streaks?

Breathing in black dust

A black sputum or mucus is often the result of breathing in black or dark dust and used to be associated with coal miners. You may notice that after you have been clearing out a dusty room or working in the garden, mucus may have black specks in it when you blow your nose or cough. The black soot that enters your nostrils might be trapped in the mucus, causing not only black snot but also black boogers.

According to the American Lung Association, being exposed to mineral dust for a long period of time can lead to pneumoconiosis. This can also be referred to as “black lung disease.” Over time, dust particles damage the lining of the lungs and can cause a chronic cough that brings up black mucus.1

Air pollution

Black spots in cough may be the result of living in an environment where there is a lot of air pollution. Pollution in the air can contain harmful chemicals and black toxic particles.

According to the journal COPD, black smoke in air pollution along with other particles can cause lung inflammation and increase mucus production. This can impact on individuals who have existing lung conditions.2

The journal Respiratory Medicine reports that other respiratory symptoms associated with exposure to air pollution can include:3

  • Breathlessness
  • A wheezing cough
  • Bronchitis-like symptoms
  • A productive cough with phlegm


Smoking can be the cause of having black mucus in the morning when you cough or blow your nose. Coughing up black goop is the result of irritation caused by smoke and tar deposits on the lungs from cigarette smoke.

According to the publication How Tobacco Smoke Causes Diseases, cigarette smoke contains high levels of oxidants and toxins. These irritants bind to the lungs and bronchi and increase mucus production while, at the same time, narrowing the airways. This can result in a chronic hacky cough and a lot of dark sputum.4

Dr. Jeffery K. Aronson from the University of Oxford commented in the journal BMJ that treacly-black phlegm can be associated with a smoker’s morning cough.5

The American Journal of Respiratory Diseases reports that black sputum is often associated with smoking cocaine.6

Smoking doesn’t just cause you to cough up black stuff, but it also increases your risk of developing lung cancer and other respiratory illnesses. To help kick “the habit”, please check out my article on 5 natural ways to stop smoking.

Coughing Up Brown, Black, or Rusty Mucus: Bacterial Infections

Coughing up rust-colored sputum in the morning or at any other time of the day can be associated with bacterial infections in the lungs.


Brown mucus or phlegm can be symptomatic of bronchitis that has developed complications. Bronchitis can be contagious when caused by a bacterial or viral infection that affects the bronchi.

The journal Respiratory Care reported that bacterial bronchitis can cause rust-colored sputum to be expelled from the lungs. Other colors of coughed-up phlegm that indicate a bacterial infection are green, yellowish-green, or yellow. The color of sputum can help doctors identify the cause of bronchitis.7

The presence of rusty colored sputum with bronchitis can also indicate that there is blood in the mucus. Dr. Laurence Knott on says that rust colored phlegm with streaks of blood can mean that the infection has gone deeper into the lungs. If you cough up rusty sputum, you should see your doctor to get checked for signs of pneumonia.8

Other symptoms of bronchitis can include:

  • Fever and chills
  • Shortness of breath
  • Chest pains and discomfort

To find out how to get rid of the symptoms of bronchitis quicker, please read my article on the best essential oils to relieve chest congestion. You may find that eating a healthy diet also helps to keep your lungs in good health.


Sinusitis can cause you to blow brown phlegm from your nose if a bacterial infection develops in your airways. Sinus infections can cause inflammation in your forehead, under your eyes, and in your nose. Very often, this results in discolored pus-like mucus to be discharged from the nose.

According to the Centers for Disease Control and Prevention, pneumococcal disease is caused by the Streptococcus pneumoniae strain of bacteria. This can cause sinusitis if the infection affects your sinuses.9 Scientists have found that this strain of bacteria can result in rust-colored sputum.7

Other symptoms of sinusitis can include:

  • Postnasal drip that irritates the back of your throat
  • Hacky coughing to bring up excess phlegm
  • Dark colored snot on your tissue after blowing your nose
  • Sneezing
  • Fatigue as your body fights the infection

Find out here about the best home remedies for sinusitis and which essential oils can help you to get rid of sinusitis and help to quickly relieve congestion from your airways.

Bacterial pneumonia

Bacterial pneumonia is a potentially serious lung infection that can result in coughing up brown phlegm.

The publication Clinical Methods explains that coughing up blood and brown mucus is common if certain bacteria strains have infected the lungs. The lung infection can cause blood-tinged fluid to build up and white blood cells mix with this red fluid. This results in a gooey substance that has a rusty appearance.10

Dr. Justina Gamache from the Olive View UCLA Medical Center says that other strains of bacteria can cause mucus that resembles redcurrant jelly.11

Pneumonia can have fatal consequences for young and elderly people. Other symptoms of pneumonia are:

  • Chest pains when breathing deeply
  • High fever
  • Confusion (in elderly people)
  • Shortness of breath

Because pneumonia can be contagious, it’s important to prevent spreading the infection to other people.


Another bacterial infection of the lungs that can result in brown, rusty, or black sputum is tuberculosis (TB). Tuberculosis is a highly-infectious disease that is spread through sputum or spit.

Researchers in the journal Deutsches Ärzteblatt International have found that mucus with streaks of blood can be a symptom of TB. Depending on the seriousness of the infection, a person may cough up brown phlegm if the blood is mixed with mucus.12

To find out more information about conditions that affect your lungs, please read my article on how to identify early signs of lung disease.

Less Common Causes of Coughing Up Brown or Black Mucus

Coughing up black or brown mucus can affect anyone if they have been breathing in dark dust particles or have an infection. However, there are some rarer causes of black snot and phlegm.

Cystic fibrosis

The journal International Archives of Medicine says that people with cystic fibrosis often develop bacterial lung infections. This can include the Streptococcus pneumoniae bacteria that turns mucus a rusty brown color.13

Chronic obstructive pulmonary disease (COPD)

Coughing up mucus with black spots in it can be a symptom of chronic obstructive pulmonary disease. COPD is usually the result of long-term exposure to irritants like smoking, coal dust, or asbestos dust. This can affect the lungs and produce a cough with thick blackish goop along with saliva.14

Fungal infection

The Journal of Cytology reports that respiratory fungal infections can cause a black yeast to grow in the airways. This results in a respiratory disorder that brings up mucus with black specks.14

How to Treat Coughing Up of Brown Mucus

If a brown mucus cough is due to a respiratory infection, then there are many natural remedies that can help cleanse your lungs naturally. Here are a few.

Garlic for chest infections

You can use garlic as a powerful antibiotic to help get rid of the symptoms of chest infections.

In fact, according to the Avicenna Journal of Phytomedicine, the antimicrobial properties of garlic can help to alleviate various respiratory diseases. Among the lung infections that garlic can help to treat are pneumonia, tuberculosis, and various bacterial and viral infections.15

You can boost the powerful therapeutic effect of garlic by adding apple cider vinegar and raw honey. Or you can find here how to make your own garlic syrup to treat chest infections.

Essential oils to clear lungs

You can help reduce the amount of brown mucus you cough up by using essential oils to clear bronchitis symptoms.

For example, eucalyptus contains a compound called cineole. The journal Cough reported on studies showing that cineole helps to reduce the amount and thickness of mucus.16 This can help to reduce the amount of brown snot you blow out of your nose or cough up.

Other essential oils that help to thin sticky respiratory mucus are:

  • Peppermint oil
  • Lavender oil
  • Tea tree oil
  • Oregano oil

How to use essential oils to ease chest congestion

To make your own vapor rub for treating bronchitis symptoms, this is what you should do:

  1. Mix 5 drops eucalyptus oil, 5 drops peppermint oil and 3 drops oregano oil with 1-oz. sweet almond oil or other carrier oil.
  2. Massage the essential oil remedy into your chest to help the vapors unblock your airways and get rid of mucus
  3. Cover with a blanket to help the essential oil mix ease congestion in your chest.

Coughing Up Black Mucus: Treatments

If your cough is black phlegm or you blow black snot from your nose, you should reduce your exposure to dust or air pollution.

Avoiding the irritants

Because black particles in the air, dust, or cigarette smoke are a major cause of dark mucus, you should do as much as you can to avoid these. Here are some ideas:

  • Stop smoking. If you smoke, the best ways to can reduce your risk of chronic lung disease and a black cough is to stop smoking.
  • Avoid secondhand smoke. It is just as important to avoid breathing in smoke from other people’s cigarettes. There are just as many toxic chemicals in cigarette smoke as smoking a cigarette.
  • Avoid air pollution in the home. Keep your home well-ventilated and eliminate all mold from your home. Airborne mold spores can affect your lungs and cause respiratory complaints.
  • Try to avoid air pollution outside. Keep away from the busiest roads and stand away from the road if you have to wait until you cross a busy intersection.
  • Wear a dust mask. If you work in a dusty environment (for example, as a stone mason or joiner), always wear a face mask to avoid breathing in dangerous dust particles.

Other Ways to Stop Coughing up Black Sputum

If you frequently cough up discolored or dark mucus, you could try some other ways to reduce the thickness of phlegm.

  • Use a humidifier. Keeping the air in your home moist can help to break up phlegm and make coughing up the sticky goop easier.
  • Use a salt water gargle. Mix 1 tsp. salt in an 8-oz. glass of warm water and gargle regularly to get rid of mucus and reduce respiratory infections. Dr. John P. Cunha on MedicineNet says that gargling with salt water can help to loosen mucus and reduce symptoms of an upper respiratory infection.17
  • Take a natural expectorant to loosen phlegm. One type of natural expectorant you can use is red clover tea to help get rid of mucus.

When to See a Doctor About Black, Brown, or Rusty Colored Sputum

If dusty environments are causing a black mucus cough, avoiding the irritants is usually enough for your mucus to return to normal. Also, treating an upper respiratory infection should stop you from coughing up dark phlegm.

When should you see a doctor if your cough is black, brown, or rusty-colored? Doctors from the National Health Service say that you should see a doctor for a chest infection in the following circumstances:18

  • Your cough contains streaks of blood or has a distinct rust color
  • Your cough symptoms continue to get worse
  • The cough persists for more than 3 weeks
  • You have a weakened immune system
  • You have an underlying health condition like heart disease, lung problems, or kidney disease

Read my other related articles:

Medical Sources

  1. LungOrg. Pneumoconiosis symptoms, causes and risk factors.
  2. COPD. 2016 Jun; 13(3): 372–379.
  3. Resp Med. 2010 June; 104(6): 880-888.
  4. NCBI. Pulmonary diseases.
  5. BMJ. 2010; 340: b5064.
  6. Am Rev Respir Dis.1992 Jan;145(1):92-100.
  7. Respir Care.2008 Apr;53(4):450-4.
  8. PatientInfo. Acute bronchitis.
  9. CDC. Pneumococcal disease.
  10. NCBI. Hemoptysis.
  11. Medscape. Bacterial pneumonia.
  12. Dtsch Arztebl Int. 2017 Jun; 114(21): 371–381.
  13. Int Arch Med. 2008; 1: 24.
  14. J Cytol. 2013 Oct-Dec; 30(4): 274–275.
  15. Avicenna J Phytomed. 2014 Jan-Feb; 4(1): 1–14.
  16. Cough. 2013; 9: 25.
  17. MedicineNet. Natural and home remedies that soothe a sore throat.
  18. NHS. Chest infection.

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