As the cold weather approaches, many begin coughing and vomiting while fighting colds and flu.
Although for most of the cases, the mucus is part of the cold season, the phlegm of color can be a sign of something more sinister.
From green and yellow to red and even black, out-of-tune mucus can indicate everything from pneumonia, tuberculosis and, in severe cases, lung cancer.
Then, MailOnline breaks down the different colors of the mucus and what they could mean for your health.
Green phlegm is often a sign of a cold or flu, while clear phlegm usually means that a person is healthy, but it can also occur excessively if they have hay fever. Black mucus can be produced in response to a fungal infection and brown mucus can be the result of pneumonia. White may indicate bronchitis, while red may be a sign that a person has TB or even congestive heart failure
Phlegm is a type of mucus that is produced in the chest and that we produce every day to eliminate the irritations of our throats and keep the airways moist.
However, it is not until most of them get sick that they do not even realize they are coughing.
Although the yellowish-green tone of the phlegm during colds usually goes away in a few weeks, it can be a sign of something more serious if it is accompanied by chest pain or shortness of breath.
Green or yellow
Usually, phlegm tinged with yellow and green is a sign that your body is fighting an infection, such as a cold.
This mucus, also known as sputum, usually begins as yellow and gradually turns green.
However, more serious infections, such as bronchitis and sinusitis, can also create phlegm of a similar hue.
Lung diseases such as chronic obstructive pulmonary disease, which cause shortness of breath, may also be at fault.
"If you have COPD, it is very likely to mean you have bacterial infections because people with COPD are much more likely to have bacteria living in their lungs, and that may mean they need antibiotics," said Dr. GP Sarah Jarvis. Sun. .
People with pneumonia and cystic fibrosis also often produce mucus that varies from yellow to green to brown and red.
The brown phlegm that appears "rusty" is often a sign of old blood in the mucus.
This may occur after producing sputum that was red or pink.
In addition to being a sign of bacterial pneumonia, brown phlegm can also be due to chronic bronchitis, which often affects smokers, and cystic fibrosis.
Inhalation of dangerous substances, such as asbestos, can also cause an incurable lung disease that leads to brown phlegm.
In severe cases, brown mucus may even be a sign of a lung abscess, which is a painful accumulation of pus that is usually caused by a bacterial infection.
Whatever the cause, brown phlegm should always prompt a visit to the attending physician, especially if accompanied by a prolonged cough.
White phlegm may be a sign of viral bronchitis and may progress to yellow-green mucus.
Gastrointestinal reflux can also cause people to cough thick, white sputum.
Like COPD, which makes the airways narrow and the lungs produce an abnormal amount of mucus.
Congestive heart failure is another culprit, which occurs when the heart gradually loses its ability to pump blood around the body.
This causes the fluid to accumulate in different areas, which can be expelled as white sputum.
Black phlegm is often a sign that it inhales something like dust, which traditionally affected coal miners.
However, it may also indicate something more sinister, such as the rare fungal infection Exophiala dermatitidis, which can occur as a complication of cystic fibrosis.
Smoking cigarettes and crack has also been linked to black mucus.
Transparent phlegm helps keep the respiratory system moist and is generally a sign that your body is healthy.
However, allergies such as hay fever can increase it, so its production is remarkable.
Viral infections such as bronchitis and pneumonia also usually start with an overproduction of clear mucus before the phlegm progresses and turns yellow or dyed green.
The production of clear mucus also naturally increases during the winter months to help warm the cold air to be less harsh in the lungs.
Red or pink
The red or pink phlegm is probably caused by blood and It can be a sign of an advanced lung infection, such as pneumonia or tuberculosis.
Congestive heart failure and a pulmonary embolism (blockage in the arteries of the lungs) may also be responsible.
In severe cases, phlegm dyed red or even coughing up blood can be a sign of lung cancer.
In addition to producing the above, you should also see your GP if you have had a cough for more than three weeks, or if you have chest pain, unexplained weight loss or difficulty breathing.