Cough With Green Phlegm: What Does It Mean?

Cough With Green Phlegm

What happens when you cough up green phlegm? Is it always an infection that needs to be treated with antibiotics? The mucosa of the respiratory system secretes this body fluid in mammals and, according to bibliographic sources, its function is to maintain the humidity of the respiratory tract.

Also, phlegm traps and facilitates the expulsion of foreign agents to the outside of the body. Because lysozymes (antibacterial substances) and antibodies are also found in it, we can say that it has antimicrobial properties.

Strange as it may be, the color of the phlegm reveals, in many cases, the nature of the patient’s pathology. This time we are going to tell you what a cough with green phlegm means, especially, and how to control it.

About phlegm and its colors

As unpleasant as it may sound, understanding where the staining of phlegm comes from and why this color change occurs is essential for detecting various diseases. Medical organizations collect the meaning of this variation:

  • Green or yellow: indicative of bronchitis, cystic fibrosis, pneumonia, and sinusitis.
  • Brown: bronchitis, cystic fibrosis, lung abscess (pus-filled cavity in the lung), pneumonia, and pneumoconiosis (lung infiltration of mineral substances).
  • White: indicates bronchitis, chronic obstructive pulmonary disease ( COPD ), congestive heart failure, and gastroesophageal reflux disease (GERD).
  • Black: fungal infection (fungus in the respiratory tract), lung abscess, pneumoconiosis, and tobacco use.
  • Red: pathologies that involve internal bleeding from the respiratory tract, such as those already described, abscesses, tuberculosis or lung cancer.

As we have seen, the colouration of the phlegm is representative of what the immune system is trying to expel from the body. A cough accompanied by brown phlegm may mean, for example, that the patient has been inhaling dirt or mineral compounds for a long period, or that there is dried blood in some portion of his respiratory tract.

On the other hand, a red colouration predicts a worrying pathology in some cases, as it can represent bleeding in some part of the body in contact with the nasal cavity and the mouth. Now, what does a cough with green phlegm mean? Then we give you the answer.

Cough with green phlegm: what does it mean?

As we have anticipated, the presence of green phlegm in the cough indicates that the body is fighting an infection. As paradoxical as it may be, this greenish colouration is due to the high number of dead white blood cells and other substances derived from the battle against the pathogen. The most common infections that give rise to this sputum are the following.

Acute bronchitis

According to the literature, acute bronchitis is the most common cause of diagnosis in people with a cough who attend outpatient clinics. In this case, we are dealing with an infection of viral origin, since rhinoviruses (causing the common cold) are the cause in 90% of cases.

Although it is not so common, we also have to point out that bacteria cause some bronchitis. According to the source above, 32% of patients with a cough for more than two weeks are infected with the Bordetella pertussis bacteria.

Some added symptoms are as follows:

  • Discomfort in the chest.
  • Fatigue.
  • Fever.
  • lessness of breath and wheezing.

Cystic fibrosis

We are facing a much more aggressive and serious pathology than that previously exposed, since it is associated with a certain risk of mortality (up to 1.33 per million inhabitants, according to studies ). The Cystic Fibrosis Foundation (CFF) reports that this disease is inherited and is characterized by a malfunction of the exocrine glands.

In a normal situation, the glands produce mucus, saliva, and other fluids that help the body function normally. In patients with cystic fibrosis, this mucus is too thick, plugging the lungs and intestines. A persistent green phlegm cough tries to get rid of this very thick and dysfunctional mucus.

Other essential data of this disease show that:

  • It is not a contagious disease.
  • To this day, there is no cure.
  • It occurs in one out of every 3,200 newborns.


According to the World Health Organization (WHO), pneumonia is the cause of 15% of all deaths in children under five years of age. It is a pathology that responds to an infection, whether of viruses, bacteria or fungi. Again, coughs with greenish phlegm are indicative of the immune fight against these microorganisms.

Some of the pathogens that cause it are the bacteria Streptococcus pneumoniae, Haemophilus influenzae type b, the pathogenic fungus Pneumocystis jiroveci and the respiratory syncytial virus. It causes a filling of the pulmonary alveoli of the patient with fluids and pus, which makes breathing painful and limits the absorption of oxygen.


A cough with greenish phlegm is typical of bacterial sinusitis. According to statistical studies carried out in the United States, this pathology affects around 31 million patients per year.

In this case, pathogenic bacteria settle in the sinuses, causing a stuffy nose, the expulsion of phlegm, and pain or pressure in the areas around the nose and eyes.

How to deal with a cough with green phlegm?

As we have seen, cough with green phlegm is indicative of an immune response to an infection or a hereditary disease, such as cystic fibrosis. There may be many natural remedies that relieve throat irritation, but depending on the severity of the pathology, medical treatments may be necessary.

In many cases, airway therapies are not essential, as they are self-solving, that is, the patient’s immune system copes with the invasion. The body is free of symptoms in about a week.

In other cases, it may be necessary to use antibiotics, inhalers to open narrowed airways in the lungs, and even surgery. The decision will be up to the professional treating the disorder.

Alex Marshall

Alex Marshall

My responsibilities include interacting with the Board of Directors, data entry, accounts payable, payroll, grant report entry, managing the organization's HR, helping and creating organizational and program budgets in collaboration with the ED and Program Direct, and other misc. tasks.

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