Cough with phlegm: what the colour of the mucus reveals
Yellow, green or even brown – in addition to the amount and consistency of the sputum when coughing, the colour of the mucus can also provide important clues as to what is happening in the respiratory tract. What different types of mucus can occur and what the colour of the sputum when coughing can indicate.
Cough with phlegm: Why is mucus produced?
When coughing with phlegm – known as a productive cough – the bronchial mucosa produces increased amounts of mucus, which is then expelled from the respiratory tract by the cough reflex. This secretion is called sputum in medicine. Although it is not very pleasant to look at, it plays an important role in the body's own mechanism for cleansing the airways: sputum binds foreign bodies, viruses or bacteria that have entered the body. Especially in cases of colds, bronchitis or other respiratory infections, productive coughing is therefore an annoying but nevertheless useful side effect.
Coughing with phlegm is a clear indication that the body is actively working to combat a respiratory tract infection. The colour of the mucus is caused by:
- components of the immune system,
- dead cells
- or inhaled substances.
The colour of the mucus can be an important signal that may provide initial clues as to the possible cause.
Clear or white discharge: classic cold mucus
Clear to whitish mucus when coughing is often a sign of a viral infection, such as a cold or acute bronchitis. The mucus is usually thick and is mainly coughed up in the morning. At the onset of a cold, a scratchy throat and dry cough are typical, which then develops into a productive cough as the illness progresses.
Yellow to green mucus when coughing: indication of inflammation
If the sputum turns yellowish or greenish when coughing, this indicates a stronger inflammatory reaction. The colour is caused by defence cells of the immune system that fight against pathogens. During an infection, the mucus often turns yellow-greenish when coughing, as the immune system works at full capacity. Yellow-green sputum when coughing can occur in viral and bacterial infections.
Brown or black mucus
Dark, brownish or black sputum when coughing usually occurs when the airways are severely strained over a long period of time, e.g. through smoking or regular inhalation of pollutants or large amounts of dust. The dark colour of the sputum is caused by deposits of smoke particles or other foreign substances that collect in the mucus. Such dark mucus colours can also occur in chronic lung diseases.
Bloody or rust-coloured sputum when coughing
If there is blood in the sputum when coughing or if the mucus has a rust-brown colour, this may be caused by minor injuries to the mucous membrane or more serious diseases of the respiratory tract or lungs. If you experience repeated coughing with bloody sputum or if it is accompanied by other symptoms such as shortness of breath, pain or fever, you should definitely see a doctor.
What helps with a cough with phlegm?
When you have a cough with phlegm, it is important to loosen the stuck mucus and soothe the bronchial tubes. Proven home remedies for coughs, such as drinking plenty of fluids, warm teas and inhalation, support the respiratory tract and can make it easier to cough up phlegm. Herbal cough remedies such as Prospan with the special ivy extract EA 575 also help to thin the mucus and relieve the bronchial tubes. This makes breathing easier and the cough often subsides more quickly.
