Call it phlegm, mucus, or sputum; regardless of your name, everybody has it. You may not give much thought to mucus until you produce it in excess. Mucus in the lungs and respiratory tract helps keep the tissues underneath moist. Most mucus production is average, but an increase in mucus can be a symptom of various illnesses. Additionally, mucus is usually clear but can become green, yellow, and cloudy in certain instances. Continue reading to find out the function of mucus and what your mucus color can tell you.
Mucus Color And Disease
While mucus usually is clear to a cloudy white color, it can change colors if an infection is present. However, mucus color alone is not the best indication of the type of infection. For instance, you may have heard that you can tell what kind of infection you have by the color of your mucus.
One of the most popular beliefs is that green mucus always indicates an antibiotic need. According to the Centers for Disease Control and Prevention, while the presence of green mucus is often a sign of an infection, it does not always mean it is a bacterial infection that requires an antibiotic. Green mucus alone is not the best way to determine the need for antibiotics. Sputum analysis and further medical tests need to be done to confirm the type of infection present.
Mucus may also become yellow if an infection is present. As a response to a condition in your respiratory tract, white blood cells increase. According to Harvard Medical School, the cells can cause the mucus to change to a yellow color. Sputum may also become brown or rust-colored, often indicating old blood in the lungs or respiratory tract.
Function of Mucus: Is Mucus Helpful Or Harmful?
It’s not uncommon to think having increased amounts of mucus means you are sick. However, you consistently produce mucus, and you probably don’t notice it. Although coughing up mucus can be annoying, it has a purpose. Mucus helps keep tissues in the nose, lungs, and throat from becoming too dry and also filters and humidifies the air you breathe. Moreover, mucus often helps trap bacteria before leading to an illness.
While the function of mucus does serve a purpose, too much can cause problems. In some instances, excess mucus production can block the airways and lead to shortness of breath. For example, excess mucus may be produced in an asthma attack, which contributes to breathing problems. In health conditions that cause an increase in mucus production, such as cystic fibrosis, it may be challenging to get mucus out of the lungs. Chest percussion is often needed, which involves pounding on the back to drain the mucus and allow it to be coughed out.
Sputum Characteristics
Sputum color is only one factor when determining the type of infection or illness present. Other characteristics are equally important and need to be evaluated, such as the following:
- Amount: It is normal to produce about 10 to 100 cc per day of mucus. Production above that may mean an infection. Additionally, certain diseases, such as COPD and cystic fibrous, often cause an increase in mucus production.
- Odor: Mucus should usually be odorless. If it has an offensive smell, it may indicate the presence of pus and indicate an infection.
- Viscosity: Viscosity refers to the thickness of mucus. The mucus should be thin, but it can become thick with various infections, like pneumonia.
What Is a Sputum Analysis?
Sputum analysis is a standard diagnostic procedure performed to test mucus for various types of infections. It is helpful to decide what type of treatment will be most effective. An analysis can also detect the presence of cancer cells.
You can obtain a sputum sample in a few different ways. The easiest and least invasive is to cough up some mucus into a sterile cup. If you cannot cough up sputum, your doctor can suction sputum through a catheter or bronchoscope tube inserted into the lung through the nose.
Once obtained, the sample is analyzed to determine if any disease-causing organisms are present, such as bacteria, viruses, or fungus. Establishing what type of organism is in the sputum can help your doctor diagnose illnesses such as tuberculosis, pneumonia, and bronchitis.
It’s normal to cough up a little mucus occasionally. However, there are some instances where mucus production, regardless of the color, should be evaluated by a doctor. You should see your doctor if you have a cough and mucus production that won’t go away after two or three weeks without a known cause. Also, if you are coughing up blood, pink or brown mucus, a medical evaluation is needed.
Resource Links:
- “Mucus and mucins in diseases of the intestinal and respiratory tracts” via Journal of Internal Medicine
- “What it takes for a cough to expel mucus from the airway” via PNAS
- “The biology of mucus: Composition, synthesis and organization” via Advanced Drug Delivery Reviews
- “Engineering the Mucus Barrier” via Annual Review of Biomedical Engineering
- “Physicochemical properties of mucus and their impact on transmucosal drug delivery” via International Journal of Pharmaceutics
