A cough with phlegm, also known as a productive cough, is the body’s defence mechanism to keep the airways clear. What are the causes? What does the colour of phlegm mean? How can you best clear the secretions? Here are some tips and information.
A cough is the body’s defence mechanism for transporting pathogens, pollen or other foreign particles out of the bronchial tubes with the aid of phlegm. If your airways are infected, for example if you have acute bronchitis or an RSV (Respiratory Syncytial Virus) infection, the bronchial tubes produce more phlegm – and this is why there is sputum when you cough.
The cough reflex ensures that we cough and that the phlegm can be released from the bronchial walls. The secretions and all of the pathogens trapped inside are propelled out of the airways towards the mouth and are then ideally spat out.
Lung specialist Prof. Fischer says: “If you have a cough with sputum, it is best to spit out the phlegm, as its colour and consistency can tell us doctors a lot about possible diseases such as asthma or a bacterial infection. But it is also safe to swallow because the phlegm is broken down in the stomach and is digested. It is not harmful to your health if you swallow it, but spitting it out can be of diagnostic value.“
Whether a cough with sputum is dangerous depends on factors such as the underlying triggers, other medical conditions you may have, how long the cough lasts, the amount and colour of the phlegm and the other symptoms. Only a trained medical professional can assess how dangerous the phlegmy cough is.
A cough is classified as productive – which means a cough with more sputum than expected – if you cough up more than about 2 tablespoons of phlegm within 24 hours. If you feel like you have a build-up of phlegm, it is advisable to spit out the secretions so that you can better assess how much there is and tell your doctor or healthcare professional the next time you see them.
If you have the following symptoms, you should immediately see a doctor:
There are many different causes of a productive cough (= cough with phlegm). The most common of these are:
The colour of phlegm may give an indication of the underlying disease:
If your phlegm is an unusual colour, you should contact your doctor. They can send your sputum (= the phlegm you spit out) to a laboratory to test it for bacteria, fungi or other germs – and may arrange further testing.
There are things you can do yourself to tackle a cough with sputum. Many of these recommendations are also advocated by healthcare professionals as part of medically prescribed therapies.
There are simple breathing exercises that help ventilate the lungs and loosen sputum, supporting the transport of secretions out of the lungs. These include breathing techniques such as the Active Cycle of Breathing Techniques, Autogenic Drainage and pursed lip breathing. Information on suitable breathing techniques can be obtained from a healthcare professional.
You should drink plenty if you have a cough with phlegm. Ideal drinks are still water, herbal teas or fruit juice diluted with sparkling water – try to avoid lots of caffeinated drinks. Improving your hydration by drinking plenty moistens the mucous membranes from the inside out, making secretions less sticky and easier to clear.
Inhalation therapy of saline solutions with a nebuliser can help liquify the phlegm and calm the airways. The fine aerosols penetrate into the bronchial tubes (unlike steam inhalation) and coat the phlegm and mucous membranes like a film. The saline solution liquifies the phlegm, which makes it easier to cough up. Inhalation devices, such as those from PARI, offer specialised products for various diseases – both for adults and for children.
Inhalation therapy with hypertonic saline solutions can help to loosen sputum. Hypertonic saline solutions are especially effective at mobilising thick phlegm in the bronchial tubes. This is because the principle of osmosis comes into play with the 3% solutions and 6% solutions. Here, water is withdrawn from the cells of the mucous membranes. This water then passes into the phlegm coating the mucous membranes. The phlegm is liquified, which is why it is then easier to cough up. Here, it is important to note that the higher the salt content, the more effectively the phlegm will be broken up and the stronger the urge to cough will be, however higher concentrations of salt can be irritating to your airways. Your healthcare professional can advise you as to how to safely try a hypertonic saline solution.
Airway clearance devices such as the PARI O-PEP use vibrations and air resistance to help release the phlegm from the bronchial walls. When you breathe out through the device, the air and airways start to vibrate slightly. In the same way as shaking a bottle of ketchup helps mobilise the ketchup, the vibrations set the secretions in the lungs in motion. The increased resistance as you exhale also helps to expand areas of your lungs, which promotes ventilation of the lungs and helps to mobilise sputum.
Input for this article was given by Dr Gemma Stanford, Clinical Specialist Physiotherapist at the Royal Brompton Hospital, London, UK.
Note: The information in this blog post is not a treatment recommendation. The needs of patients vary greatly from person to person. The treatment approaches presented should be viewed only as examples. PARI recommends that patients always consult with their physician or physiotherapist first.
An article written by the PARI BLOG editorial team.
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