The fastest way to deal with phlegm is to thin it out so your body can clear it more easily. That means staying well hydrated, keeping the air around you moist, and using a few simple techniques to move the mucus up and out of your airways. Most phlegm resolves on its own within a couple of weeks, but thick, persistent mucus can be loosened with both home remedies and over-the-counter options.
Why Your Body Makes Extra Phlegm
Phlegm is just mucus that comes from your lungs and lower airways rather than your nose. It’s made of water, electrolytes, and enzymes that trap germs, dust, and other irritants before they reach deeper into your lungs. When your airways are inflamed from a cold, allergies, or an irritant like cigarette smoke, they ramp up mucus production and the mucus itself becomes thicker and stickier.
Common triggers include upper respiratory infections (colds and flu), sinus infections, allergies, asthma, acid reflux that irritates the throat, smoking, and breathing dry or polluted air. Figuring out what’s driving the excess phlegm helps you pick the right strategy, but regardless of the cause, thinning the mucus and helping it drain are the core goals.
Stay Hydrated to Thin the Mucus
Your airway lining depends on water moving across cell membranes to keep mucus at the right consistency. When you’re dehydrated, less water permeates into the mucus layer, and the secretions become concentrated and sticky. Breathing through your mouth or breathing dry air accelerates water loss from the airway surface, compounding the problem. Drinking plenty of fluids throughout the day, especially warm ones like tea or broth, helps replenish that water supply from the inside.
There’s no magic number of glasses per day that’s been clinically proven to thin phlegm, but the principle is straightforward: dehydration makes mucus worse, and adequate hydration keeps it loose enough for your cilia (the tiny hair-like structures in your airways) to sweep it upward. If your urine is pale yellow, you’re likely drinking enough.
Use Humidity to Your Advantage
Dry indoor air pulls moisture from your airway lining and thickens phlegm. A humidifier in your bedroom can counteract this, but the target range matters. Aim for 30 to 50 percent relative humidity. Below 30 percent, the air is too dry to help. Above 60 percent, you risk mold growth and dust mites, which can trigger more mucus production, especially if you have asthma or allergies.
A hot shower works on the same principle. Standing in a steamy bathroom for 10 to 15 minutes lets you inhale warm, moist air that loosens phlegm in your chest and sinuses. You can also drape a towel over your head and breathe the steam rising from a bowl of hot water for a more targeted approach.
Try Saline Rinses and Gargles
Saltwater is one of the simplest and most effective tools for phlegm. For nasal and sinus congestion that drips into your throat (postnasal drip), a saline nasal rinse using a neti pot or squeeze bottle flushes out mucus and irritants directly. Use distilled or previously boiled water to avoid introducing bacteria.
For phlegm that sits in the back of your throat, gargling with warm salt water (about half a teaspoon of salt in a cup of warm water) can help break it up and soothe irritated tissue. Research on nebulized saline in clinical settings shows that slightly saltier solutions can improve mucus clearance compared to normal saline, reducing symptom severity. You won’t replicate a nebulizer at home, but even a basic saltwater gargle offers noticeable relief.
Honey as a Cough and Phlegm Remedy
Honey has real evidence behind it, though the picture is nuanced. A systematic review published in BMJ Evidence-Based Medicine pooled data from multiple trials and found honey performed about as well as dextromethorphan (the active ingredient in most OTC cough suppressants) at reducing cough frequency and severity. It outperformed diphenhydramine, an antihistamine sometimes used for coughs, across combined symptom scores, cough frequency, and cough severity.
Against placebo, results were mixed. Some studies showed a significant benefit, others didn’t. The practical takeaway: a spoonful of honey, or honey stirred into warm water or tea, is a reasonable first-line option, especially if you’d rather skip medication. It coats the throat and may calm the cough reflex that phlegm triggers. Do not give honey to children under one year old due to the risk of botulism.
Over-the-Counter Expectorants
Guaifenesin is the only OTC expectorant widely available, sold under brand names like Mucinex and Robitussin Chest Congestion. It works by increasing the volume of fluid in your airways while reducing the stickiness of the mucus, making your coughs more productive. In other words, it doesn’t stop you from coughing. It makes each cough more effective at moving phlegm out.
The standard adult dose is 600 mg taken twice a day in extended-release form. It works best when you drink plenty of water alongside it, since the drug relies on hydration to do its job. If your main problem is a dry, hacking cough rather than thick mucus, a cough suppressant containing dextromethorphan may be more appropriate. Avoid combining a suppressant with an expectorant, since suppressing the cough defeats the purpose of loosening the phlegm.
Physical Techniques to Clear Your Chest
Gravity can help drain mucus from different parts of your lungs, a technique called postural drainage. The basic idea is to position your body so that the section of your lungs with the most congestion is above the airway opening, letting mucus flow downward toward your throat where you can cough it out. Depending on where the congestion sits, you might lie on your back, stomach, or side, sometimes with a pillow elevating your hips above your chest.
A simpler version: lie on each side for five to ten minutes and follow with a controlled cough. You can also try “huff coughing,” where you take a medium breath and then exhale forcefully in short bursts (like fogging a mirror) rather than doing a full, deep cough. This moves phlegm from smaller airways into larger ones without the throat irritation of a hard cough. For people with chronic lung conditions, a healthcare provider can recommend specific positions tailored to where mucus tends to accumulate.
What Phlegm Color Actually Tells You
Many people assume green or yellow phlegm means a bacterial infection that needs antibiotics. The reality is less clear-cut. Phlegm changes color when white blood cells flood the mucus to fight an infection, and that happens with viral infections too. A study in Clinical Microbiology and Infection found that patient-reported sputum color was not a reliable marker for bacterial involvement. Even mucoid (clear or white) samples showed bacterial growth 78 percent of the time in people with chronic lung disease, while plenty of green and yellow samples turned out to be viral.
Color can offer loose clues. Brown or black phlegm often relates to inhaled irritants like cigarette smoke or air pollution. Pink or red-tinged phlegm can mean minor bleeding from irritated airways, which sometimes happens after repeated forceful coughing. But you can’t diagnose yourself based on color alone, and green phlegm by itself is not a reason to request antibiotics.
When Phlegm Signals Something Bigger
Most phlegm from a cold or respiratory infection clears within two to three weeks. A cough that lasts eight weeks or longer in adults, or four weeks in children, is classified as chronic and warrants investigation. Persistent phlegm production at that point could indicate asthma, chronic sinusitis, acid reflux, or a more serious lung condition.
Seek evaluation sooner if your phlegm contains blood, if the congestion is accompanied by a fever that returns after initially improving (a possible sign of secondary bacterial infection), if you’re experiencing shortness of breath or wheezing, or if the phlegm is interfering with sleep or daily function. These symptoms don’t always mean something dangerous, but they do mean the phlegm isn’t going to resolve with steam and honey alone.