Most extra mucus from a cold or other infection clears as the illness passes. Drinking enough fluid, huffing, controlled coughing, and in some people postural drainage or medicines help move it. Mucus that lasts, changes color, or comes with fever, breathlessness or chest pain needs a clinician, because the cause matters more than the technique.
Will mucus in the lungs go away on its own?
Often, yes. Cleveland Clinic says excess mucus is usually something you deal with while you are sick, as your body clears out germs and dead immune cells. Medical News Today says most adults recover from a cold within about a week.
It is less likely to settle by itself if something keeps producing it. The American Lung Association says people with COPD, cystic fibrosis or bronchiectasis may have more, thicker or stickier mucus in their airways.
Why won't my phlegm and mucus go away?
The sources used here name these common reasons:
- Infection. Sinusitis and respiratory infections are the most common cause of excess thick mucus, per Cleveland Clinic.
- Allergies and irritants. These can cause excess clear mucus. Chemicals, fragrances and pollution can also irritate the lower airways, per Medical News Today.
- Chronic lung disease. Bronchiectasis, COPD and other chronic lung diseases can cause mucus buildup. In cystic fibrosis the mucus is thick and sticky.
- Smoking, vaping and secondhand smoke. The American Lung Association says the chemicals in tobacco products, like nicotine, produce thicker mucus and more of it.
- Dry air or dehydration. Medical News Today says dry air can make the nose and throat produce more mucus, and that the body needs to stay hydrated to keep mucus thin.
- Acid reflux. Medical News Today says reflux can increase phlegm and mucus.
- Decongestants. Medical News Today says they dry secretions but may make phlegm and mucus harder to get rid of.
A clinician can work out which applies to you. The American Lung Association says a sputum culture can check a sample for bacteria or fungi, and a chest X-ray or CT scan may also be ordered.
How long is too long for mucus?
| Situation | What the source says |
|---|---|
| Cough lasting more than 10 days | Medical News Today lists this as a reason to seek medical attention. |
| Mucus increase that is new or getting worse | The American Lung Association says it could be a lung infection. Other signs include fever, a mucus-producing cough, shortness of breath or chest pain. |
| Unusual color (bright yellow or green), very dark, or a lot of blood | Cleveland Clinic says to see a healthcare provider, who can decide whether an infection needs treatment. |
| Unpleasant-smelling nasal discharge, blurred vision with a stuffy nose, or yellow or white spots at the back of the throat | Medical News Today lists each as a reason to seek medical attention. |
Color alone does not identify an infection. Cleveland Clinic says it cannot diagnose a specific illness, and Medical News Today says colored mucus may show the immune system fighting a virus, or simple dehydration. Treat the color as a prompt to check in, not a diagnosis.
What can I drink to flush out mucus?
No drink flushes mucus out. Fluids help keep it thin enough to cough up. The American Lung Association says water keeps mucus thinner and easier to cough up.
The Bedfordshire Hospitals NHS Trust leaflet gives more detail:
- It suggests up to 4 pints (8 glasses) a day of water, decaffeinated tea or coffee, or other drinks.
- It advises avoiding caffeine, saying caffeine makes you pass water out before it has had a chance to work in your body.
- If you take “water tablets” (diuretics), it says to check with your GP how much you should drink.
- It suggests a glass of unsweetened pineapple juice, or a small amount of pineapple, which it says may help break down mucus. It advises against canned pineapple and says to use it with caution if you have diabetes or reflux, because pineapple is sugary and acidic.
Medical News Today also suggests warm, noncaffeinated drinks and avoiding alcohol and caffeine, which can dehydrate you in excess.
How do I break up mucus stuck in my chest?
The common idea behind every technique is to get air behind the mucus, loosen it, and move it to larger airways where you can cough it out. That is how Pulmonary and Critical Care of Atlanta describes it.
| Method | What it involves | Who should guide it |
|---|---|---|
| Huffing | Breathe in, then breathe out through an open mouth as if steaming up a mirror. | Can be learned from a leaflet or video. A physiotherapist can check your technique. |
| Controlled coughing | Seated, breathe in slowly, hold 3 to 5 seconds, then 2 or 3 short, sharp coughs as you breathe out. | Described by MyHealth Alberta for anyone with too much mucus. |
| Postural drainage | Lie in positions that let gravity drain mucus from parts of the lungs. | Bedfordshire says positions are specific and need to be taught by a respiratory physiotherapist. |
| Chest percussion | Cupped hands lightly clap the chest and back. | Bedfordshire says do not try it, or have someone else do it, unless a physiotherapist has taught you. |
| Devices | Vibrating vest, PEP device, airway oscillating device. | Need a prescription or assessment. |
Huff cough steps
The American Lung Association describes the huff cough this way: sit upright in a chair with both feet on the floor and take a deep breath in through your nose. As you breathe out, open your mouth and make a “huff” sound in your throat, huffing 2 to 3 times. Relax and repeat as needed.
Controlled coughing steps
MyHealth Alberta says uncontrolled coughing makes things worse because it closes the airways and traps mucus. Its steps:
- Sit on the edge of a chair with both feet on the floor. Lean forward a little and relax.
- Breathe in slowly through your nose with your arms folded over your belly.
- Hold your breath for 3 to 5 seconds.
- Lean forward as you breathe out, pushing your arms against your belly.
- Cough 2 or 3 times as you exhale with your mouth slightly open, making the coughs short and sharp.
- Inhale again slowly and gently through your nose, not with quick, deep breaths through your mouth. Rest and repeat if needed.
MyHealth Alberta says it is best to do this after using your inhaler or other medicine.
Postural drainage, as MyHealth Alberta describes it
It says to hold each position for at least 3 minutes, though your doctor or therapist will tell you how long. Do it about 30 minutes after your inhaler and on an empty stomach. To drain the front of the lungs, keep your chest lower than your hips with two pillows under your hips. For the sides, use two or three pillows under your hips, then turn over to drain the other side. For the back, put two or three pillows under your hips and kneel over them. Do belly breathing in each position, and if you need to cough, sit up and do controlled coughing. Ask your clinician before trying this, especially if you have a heart or lung condition.
What exercises remove mucus from the lungs?
The Bedfordshire leaflet describes a three-part breathing cycle, repeated 3 times:
- Tummy breathing. Breathe gently in through your nose and out through your nose or mouth, with a hand on your tummy and shoulders relaxed.
- Deep breathing. A long, slow, deep breath in, with a 3 to 5 second hold if you can, then a gentle breath out. Repeat three times.
- Huffing. A half-sized breath in, then breathe out onto your hand with your mouth open. Repeat from a full breath in.
The leaflet also says general exercise makes you take deeper breaths, which helps move mucus from low in the lungs, and that exercise strengthens the breathing muscles so your cough is stronger. It says it can help to use a reliever inhaler before breathing exercises, if you have one prescribed. Your own prescriber should confirm that.
What medicine removes mucus from the lungs?
| Type | What the sources say |
|---|---|
| Expectorants (guaifenesin) | Medical News Today says they thin mucus so coughing clears the airways, and that guaifenesin is the only over-the-counter expectorant in the United States. It comes as fast-acting tablets, extended-release tablets and liquids. |
| Mucolytics (hypertonic saline, acetylcysteine, dornase alfa) | Pulmonary and Critical Care of Atlanta says inhaled hypertonic saline and acetylcysteine thin mucus by drawing water into the airways, and dornase alfa is used specifically for cystic fibrosis. Cleveland Clinic says mucolytics treat chronic lung diseases like cystic fibrosis. These are prescribed. |
| Bronchodilators (albuterol, ipratropium, levalbuterol) | The Atlanta practice says they relax the airways and are used before airway clearance. It describes a sequence of bronchodilator, then mucolytic, then the clearance technique, then any inhaled antibiotic. That applies to people prescribed these medicines; follow your own clinician's plan. |
| Decongestants and antihistamines | Cleveland Clinic says decongestants temporarily reduce inflammation and mucus in the nose and throat, and antihistamines calm allergic reactions that cause too much mucus. Medical News Today cautions that decongestants may make phlegm harder to clear. |
| Nasal rinses and saline sprays | For nose and sinus mucus. Medical News Today says to use sterile or distilled water when rinsing. |
The American Lung Association says you should always speak with your healthcare provider before starting any new medication.
Why isn't Mucinex working, and what are the downsides?
The sources used here do not explain why a particular person gets no benefit from Mucinex, and they do not list its side effects. They do give some leads:
- Pulmonary and Critical Care of Atlanta lists guaifenesin, found in Mucinex and other common cold remedies, as a mucus thinner. It is not a treatment for the cause of the mucus.
- Medical News Today says people taking guaifenesin should stay hydrated and follow all doctor recommendations. It adds that some guaifenesin products also contain acetaminophen and pseudoephedrine hydrochloride for fever reduction and decongestion. Check the label for the active ingredients in what you bought. Decongestants may make mucus harder to clear.
- The Bedfordshire leaflet says that if mucus is particularly thick even when you are drinking the right fluids, your GP or consultant might prescribe extra medication.
- Persistent mucus may have a cause a cough medicine does not address, such as chronic lung disease, smoking or reflux.
If it is not helping, ask a pharmacist or clinician what else to try and whether it is safe alongside your other medicines. Do not stack products on your own, especially those with overlapping ingredients.
How do I get rid of a stubborn cough and mucus?
Medical News Today says not to suppress a cough, because coughing is the body's way of keeping secretions out of the lungs and throat, and suggests using cough syrups sparingly, if at all. Other steps it lists:
- Keep the air moist with a cool mist humidifier.
- Take a hot bath or shower; steam helps loosen mucus in the nose and throat.
- Sleep with your head elevated.
- Gargle with salt water (one teaspoon of salt in a glass of warm water).
- Blow your nose gently. Blowing too forcefully may hurt the sinuses.
- Avoid irritants and keep allergies in check.
It lists eucalyptus products as a remedy used for years to subdue coughs and reduce mucus. The page gives no evidence of how well it works, so ask a clinician before relying on it.
If the cough stays past 10 days, or comes with fever, breathlessness or chest pain, see a clinician.
Should I swallow phlegm or spit it out?
Swallowing it is not harmful, per both Cleveland Clinic and Medical News Today. Cleveland Clinic says it is fine to spit it into a tissue if swallowing makes you cough or feels like it gets stuck, then wash your hands. Medical News Today says neither spitting nor swallowing will likely help you recover faster.
How do I clear mucus from my lungs after smoking?
The American Lung Association lists quitting smoking and vaping as a step, and says support is available through the association. Cleveland Clinic says smoking or toxins in the air can cause brown mucus, although brown mucus can also signal infection. Medical News Today says a person may have restored mucus function in the lungs within about 1 to 12 months of quitting tobacco. If you smoke and have mucus every day, a cough that is changing, or blood in it, ask a clinician about it.
Is there a recipe to clear your lungs in 3 days?
The sources used here contain no 3-day lung-clearing recipe, cleanse or detox, and no timeline for clearing the lungs. What they do describe are the everyday measures above: fluids, huffing and controlled coughing, exercise, and avoiding smoke and irritants. A product or video promising a fast lung cleanse is making a claim you can ask a clinician or pharmacist to check.
If you are weighing a lung supplement, you can read about that product on the Pulmo Balance page. For background on how the airways clear themselves, see how mucociliary clearance works, and for a broader overview see our natural mucus guide.
Why does clearing mucus matter?
The Bedfordshire leaflet says uncleared mucus can cause ongoing inflammation and infection, and that repeated chest infections can contribute to deterioration in lung function. In chronic lung disease, it says the cilia (tiny hairs that move mucus toward your mouth) are less efficient and mucus is thicker. This is why people with COPD, bronchiectasis or cystic fibrosis are often taught airway clearance routines.
What could not be verified here
- Which drink, food or herbal remedy works fastest. The sources give general hydration advice, not a ranking.
- Mucinex side effects, doses and comparison with other products.
- Any 3-day plan for clearing the lungs.
- Experiences shared in online forums, which are not part of the sources used here.
To find out what applies to you, a primary care clinician or a lung specialist can look for the cause. The American Lung Association HelpLine (800-LUNG-USA) lists respiratory therapists and nurses who can answer lung questions.
This page is general information, not a diagnosis, and it does not replace advice from your own clinician. Check any change in medicines with them.
By SterlingMedicalCenter.org Editorial Team
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