Pneumonia Brown Phlegm

About Pneumonia

Pneumonia is an infection where the air sacs (alveoli) in one or both lungs are inflamed, which may result in the air sacs being filled with fluid or pus. Pneumonia may be caused by bacteria, viruses, and fungi with signs and symptoms ranging from mild to severe, including a cough that may or may not be accompanied by mucus, difficulty in breathing, fever, and chills. The severity of pneumonia depends on age, overall health condition, and the cause of the infection. 

Common Causes

Pneumonia may be caused by bacteria, viruses or fungi such as:


The most common cause of community-acquired pneumonia is Streptococcus pneumonia,  which is also the most common cause of pneumonia in the UK1. Bacterial pneumonia frequently affects only one lobe of the lung. When this occurs, the condition is known as lobar pneumonia. People recovering from surgery, those with lung disease or viral infection, and those with compromised immune systems are the most vulnerable to bacterial pneumonia. Other bacteria can also cause a kind of pneumonia that is referred to as “atypical” pneumonia because infection with these bacteria causes slightly different symptoms, has a different appearance on X-ray, and respond differently to some antibiotics than typical bacteria that cause pneumonia. The other forms of bacteria are2 -

  • Mycoplasma pneumonia: a microscopic widespread bacterium that typically infects people under the age of 40, particularly those who live and work in crowded surroundings. The illness is often mild and usually goes unnoticed. It is usually referred to as walking pneumonia.
  • Chlamydophila pneumonia: It causes upper respiratory infections all year but can also cause mild pneumonia.
  • Legionella pneumophila: It causes Legionnaire's disease, a potentially fatal form of pneumonia. Legionella, unlike other bacterial pneumonia, is not transmitted from person to person. Exposure to contaminated water from cooling towers, whirlpool spas, and outdoor fountains has been related to outbreaks of the disease. 


Pneumonia can be caused by viruses that invade the upper respiratory tract. The most prevalent cause of viral pneumonia in adults is SARS-CoV-2, COVID-19 virus, and the influenza virus. Respiratory syncytial virus (RSV) is the most common cause of viral pneumonia in young children. Most viral pneumonias are not dangerous and last much shorter than bacterial pneumonia. 

COVID-19 pneumonia can be severe, resulting in low oxygen level in the blood, respiratory failure, and, in many cases, acute respiratory distress syndrome (ARDS). 

SARS-CoV-2 virus-induced pneumonia usually affects both lungs. As the lungs fill with fluid, oxygen exchange becomes more difficult, resulting in breathing difficulties. It may take months for symptoms to subside. 

The influenza virus can cause severe and possibly fatal viral pneumonia. The virus infiltrates and multiplies in the lungs, yet there are essentially no visible symptoms of lung tissue filling with fluid. This pneumonia is more dangerous in those who already have heart or lung illness, as well as pregnant women2.


Fungal pneumonia is particularly common in those who have chronic health problems or compromised immune systems. People who have been exposed to high concentrations of specific fungi through polluted soil or bird droppings also have higher risk of developing fungal pneumonia. 

Pneumocystis pneumonia is a potentially fatal fungal infection caused by the fungus Pneumocystis jirovecii2. It is rare in the UK, however there is a high risk among those who are immune compromised. 


Depending on the cause, age and the overall state of one’s health, the symptoms of pneumonia may vary from mild to severe. Mild symptoms include cold and flu but last longer. Other symptoms include3

  • Chest pain when breathing or coughing 
  • Adults aged above 65 may experience confusion or changes in mental health
  • Cough that is accompanied by the production of brown phlegm 
  • Fatigue, chills, fever, and sweating 
  • Persons above 65 or with a weak immune system may experience a lower-than-normal body temperature 
  • Nausea, vomiting or diarrhoea 
  • Shortness of breath

Other causes of brown phlegm

Although phlegm is composed of mucus membranes, it is produced and utilized by the respiratory system to treat inflammation. Apart from pneumonia, other causes of phlegm include cold, sinusitis, allergies, exposure to smoke or pollution4

Other colours of phlegm

Different colors of phlegm may give information on what is happening in the lungs and other respiratory organs. Some colors of phlegm and their significance include5 -

  1. Clear: Clear phlegm is common. It is made up of water, salts, antibodies, and immune system cells. After it is produced in the respiratory system, most of it travels down the back of the throat before being swallowed.
  2. Brown and black: While it is most likely due to previous bleeding, it could also be a sign of a chronic infection, such as bronchitis. Smokers may also have brown phlegm. Black phlegm on the other hand may be an indication of a fungal infection, a history of smoking or inhaling substances regularly.
  3. White:  White phlegm is an indication of congestion of the nasal cavity. When the nasal cavity is clogged, the tissues swell and become irritated, slowing the movement of mucus through the respiratory tract. When this happens, the phlegm thickens and becomes cloudy or white.
  4. Yellow:  Yellow phlegm may suggest immune cells working at the site of infection or other forms of inflammatory conditions. As white blood cells carry out their function of fighting germs, phlegm picks up these germs giving a yellow trace of colour. 
  5. Green:  A green phlegm implies an extensive and powerful immunological response. The green colour of phlegm is caused by white blood cells, bacteria, proteins and other cells produced by the body during the immunological response. While this color phlegm may indicate an illness, antibiotics are not always required. Most viral infections that cause green phlegm disappear without therapy within a few weeks. 
  6. Red: Red colored phlegm is like to be an indication of blood. Among the many reasons why blood is found in phlegm could be 
  • Due to a lot of coughing resulting to breaking of small blood vessels in the lungs 
  • Airways bleeding due to excess coughing 
  • Abscesses 
  • Tuberculosis 
  • Lung cancer 
  • A nosebleed can occur when there is swelling in a person's nasal tube. This can result in blood seeping into the postnasal drip, which they then cough up. 


Children, elderly people, and people with pre-existing medical condition such as diabetes are most likely to experience complications with pneumonia. Possible complications of pneumonia include6

  • Pleurisy: A condition where there is an inflammation between the thin lining of the ribcage (pleura) and the lungs which could eventually lead to respiratory failure.
  • Lung abscess: This complication rarely happens and but it does, it occurs in people with prolonged pre-existing illnesses or chronic history of alcohol misuse. 
  • Blood poisoning:  This is a rare and serious complication whereby the infection gets into the blood (sepsis)
  • Acute respiratory distress syndrome (ARDS): A severe form of respiratory failure. 


Ensuring good hygiene practices forms the backbone of preventing pneumonia. Some good hygiene practices that may help one prevent pneumonia are -

  • Covering the mouth with a handkerchief or tissue when coughing or sneezing 
  • Throwing away used tissues or handkerchiefs ( washing) immediately 
  • Washing the hands regularly to avoid the transfer of germs 
  • Living a healthy lifestyle such as quitting smoking or avoiding it completely as it may damage your lungs
  • Avoiding excessive alcohol consumption could help prevent pneumonia. As alcohol makes the lung’s natural defence system weak, causing one to be more vulnerable to pneumonia. 
  • Pneumococcal and influenza vaccines can also prevent vulnerable populations from infections.

When to seek medical advice

It is advisable to seek medical attention when you do not feel well and are presenting symptoms of pneumonia. When faced with the following symptoms, you should contact a Physician: 

  • Forceful breathing
  • Coughing with blood
  • Face (predominantly the area near the lips) showing a bluish hue (due to poor oxygen flow)
  • Feeling confused or drowsy
  • Difficulty in peeing
  • Collapse or faint


Pneumonia can be diagnosed either through a chest x-ray, blood test, sputum culture, pulse oximetry, chest CT scan, bronchoscopy, or pleural fluid culture. 


The cause of pneumonia will determine the type of treatment that is needed. While antibiotics are used to treat bacterial pneumonia, viral pneumonia usually goes away on its own. Getting enough rest, eating well, increasing fluid in take, taking pain medicine, taking cough relief medicine and oxygen therapy can also help treat pneumonia.


An inflammation of the air sacs of one or both lungs is known as pneumonia. These air sacs may be filled with fluid or pus resulting in coughing which most likely will be accompanied by the production of phlegm. Pneumonia presents itself with fever, chills, cough with phlegm of different colours, and difficulties in breathing. Bacteria, viruses, and fungi are the main causes of pneumonia. The symptoms of pneumonia may range from mild to severe. Children, older adults, and people with pre-existing health conditions are at most risk. Practising personal hygiene and a healthy lifestyle forms the backbone of preventing pneumonia.Eating well, resting enough, and taking pain and cough medicine can help treat pneumonia. 


  1. Shoar S, Musher DM. Etiology of community-acquired pneumonia in adults: a systematic review. Pneumonia (Nathan). 2020; 12:11.
  2. What Causes Pneumonia? [Internet]. [cited 2022 Nov 7]. Available from:
  3. Pneumonia - Symptoms and causes. Mayo Clinic [Internet]. [cited 2022 Nov 7]. Available from:
  4. Phlegm and Mucus: How To Get Rid of It. Cleveland Clinic [Internet]. 2022 [cited 2022 Nov 7]. Available from:
  5. Yellow, Brown, or Green Phlegm: What It Means. Healthline [Internet]. 2022 [cited 2022 Nov 7]. Available from:
  6. Pneumonia. [Internet]. 2017 [cited 2022 Nov 7]. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Fuanyi Awatboh

M.Sc. in Epidemiology and Control of Infectious Diseases, University of Buea, Cameroon

I am a professional Quality Assurance Mentor with Global Health Systems Solutions. My job is to enhance HIV testing, Care, and treatment by making sure that all entry points in the three hospitals under me follow standard testing algorithms, have all necessary tools and equipment needed for testing, train testers if need be, and monitor that all positive cases are under treatment among other duties. I have also mentored laboratories to increase their quality of service and standards of operations.

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