People with bronchitis have a persistent cough that produces clear, yellow, or green phlegm. Green phlegm often points to a bacterial infection. However, this is less common with bronchitis than viral infection.
Bronchitis is an infection of the airways in the lower respiratory tract that usually results from viruses similar to those that cause a cold. Sometimes, bacteria, fungi, or foreign substances are responsible. Thick mucus builds up in the airways, and a person develops an ongoing cough that brings up the mucus.
The color of this mucus can highlight the type of infection and other lung health problems. However, bronchitis is one of many conditions that can lead to excess phlegm, and while phlegm’s color provides some information on health status, it does not provide the whole picture.
This article explains the link between phlegm color and bronchitis.
According to the United Kingdom’s National Health Service (NHS), a person with bronchitis may cough up yellow, green, white, or clear phlegm, also known as sputum. This color can change over time, for example, from white to green and yellow.
People with chronic or long-lasting bronchitis may find that phlegm has flecks of red where blood has entered the sputum, according to
Phlegm can have a range of colors, including no color at all. This table illustrates the range of health implications they may have.
| Color | Implication |
|---|---|
| clear | This indicates no disease in small amounts. Large amounts may point to a lung condition. |
| white/gray | This can also suggest that no disease is present, but a lot of sputum may still suggest a lung condition. |
| darker yellow/green | This usually points to bacterial infections, including pneumonia or lung infection. It is also common in people with cystic fibrosis, a condition that leads to mucus buildup in the lungs. |
| brown | People who smoke often have brown sputum. It can also indicate a condition known as black lung disease that develops after ongoing exposure to coal dust. |
| pink | This may suggest a fluid buildup in the lungs, known as pulmonary edema. This often occurs in people with heart failure. |
| red | This can be an early sign of lung cancer or indicate a life threatening blood clot in the lung. Red sputum means that a person should call 9-1-1 immediately. |
However, the presence of peroxidase, an enzyme that immune cells release, can also alter the color of phlegm, so green phlegm does not suggest a bacterial infection on its own.
Healthcare professionals can request a sputum culture, which is a lab test to identify potential bacterial or fungal causes of bronchitis. Increased amounts, rather than specific colors, indicate diseases of the lungs and airways.
Bronchitis can cause
These include:
These generally resolve after 2 to 3 weeks. If a phlegmy cough continues for 3 months or longer, healthcare professionals would consider it to be chronic.
Read more about bronchitis symptoms.
Bronchitis treatment generally involves soothing symptoms and helping people feel better during recovery. Acute bronchitis usually passes without treatment. However, the following measures
- taking over-the-counter medications to reduce coughing or make mucus looser, although research is ongoing into whether these are useful for acute bronchitis
- consuming hot drinks, such as water or tea with honey
- using a humidifier
- taking inhaled medications if a doctor prescribes them, such as albuterol
If a healthcare professional diagnoses a bacterial infection through a sputum culture or other diagnostic methods, including blood tests, they may prescribe antibiotics. For people with chronic bronchitis, a healthcare professional may recommend the following:
- quitting or avoiding smoking
- using medications to clear the airways
- having oxygen therapy to support healthy breathing
- undergoing pulmonary rehabilitation, which teaches people breathing techniques and prevents disease progression
Read more about treatment for bronchitis.
Seeking a clinical opinion on bronchitis is crucial if a person notices several persistent or escalating symptoms,
- a cough that produces blood-stained or red mucus
- a cough that continues to produce mucus after 2 to 3 weeks
- a cough that gets worse
- breathing difficulties
- intermittent chest pain
- severe illness
People who develop bronchitis symptoms and are pregnant, over 65 years of age, or living with a compromised immune system should contact a doctor. The same applies to those with underlying diabetes or a known lung, kidney, or heart disorder.
How long does it take for bronchitis phlegm to go away?
In acute bronchitis, people usually stop coughing up phlegm within 3 weeks, according to the NHS. Those with chronic bronchitis may have a phlegm cough for 3 or more months.
What color mucus is bad to cough up?
Red phlegm may indicate early lung cancer or a blood clot traveling to the lung from elsewhere in the body, which can be fatal.
Pink phlegm may indicate fluid buildup due to heart failure. Large amounts of clear or yellow phlegm may also suggest lung disease.
Bronchitis means that a person may cough up excess amounts of clear, white, yellow, or green phlegm.
Sometimes, green phlegm can point to a bacterial cause. Other colors, such as brown, pink, or red phlegm, may suggest severe or life threatening health problems.
People should consider speaking to a healthcare professional if they continue to cough up phlegm for 3 or more weeks.