The fastest ways to clear phlegm from your throat and chest include drinking hot fluids, using a specific coughing technique called huff coughing, inhaling steam, and taking an over-the-counter expectorant. Most phlegm from a cold or respiratory infection clears on its own within 10 to 21 days, but these methods can speed things along and make you more comfortable in the meantime.
Why Your Body Makes Phlegm
Phlegm exists for a reason. Your airways are lined with cells that produce a thin layer of mucus, which is about 97% water with small amounts of proteins and salt. This mucus traps dust, bacteria, viruses, and other particles you inhale. Tiny hair-like structures called cilia then beat in coordinated waves, about 10 to 20 times per second, pushing that mucus upward toward your throat where you swallow or cough it out.
When you’re sick or dealing with allergies, your body ramps up mucus production and the mucus itself gets thicker. That’s when you feel it sitting in your chest or coating your throat. The goal isn’t to stop mucus production entirely. It’s to thin it out and help your body move it along faster.
Drink Hot Fluids, Not Cold
Temperature matters more than you might think. In a study of 15 healthy subjects, sipping hot water increased the speed at which nasal mucus moved from 6.2 to 8.4 millimeters per minute. Hot chicken soup did even better, pushing it from 6.9 to 9.2 millimeters per minute. Cold water, on the other hand, actually slowed mucus movement down significantly, dropping it from 7.3 to 4.5 millimeters per minute.
The effect comes partly from inhaling the steam as you sip and partly from the heat itself. Hot chicken soup appeared to have an additional benefit beyond just hot water, possibly from its aroma or taste compounds stimulating mucus flow. The boost is temporary, returning to baseline after about 30 minutes, so sipping hot fluids throughout the day is more effective than one big cup in the morning. Tea, broth, and warm water with lemon all work.
Try the Huff Cough Technique
Regular coughing can leave you exhausted without actually moving much phlegm. The huff cough is a technique used in respiratory therapy that moves mucus from your smaller airways into larger ones where you can actually clear it. Think of it as the motion you’d use to fog up a mirror.
Here’s how to do it:
- Breathe in slowly through your nose, filling your lungs about three-quarters full.
- Hold for two to three seconds. This gets air behind the mucus sitting in your airways.
- Exhale slowly but forcefully with your mouth slightly open, like you’re fogging a mirror. This is the “huff.” It pushes mucus from smaller airways into larger ones.
- Repeat one or two more times, then follow with one strong, deliberate cough to clear the mucus from your larger airways.
Do two or three rounds depending on how congested you feel. One important detail: don’t gasp or breathe in quickly through your mouth right after coughing. Quick breaths can push mucus back down and trigger uncontrolled coughing fits. Instead, breathe in gently through your nose between rounds.
Use Steam Safely
Steam inhalation loosens thick mucus and adds moisture to irritated airways. Sessions of 5 minutes at a time, repeated two or three times per day, are a standard approach. You can do this by leaning over a bowl of hot water with a towel draped over your head, or simply by sitting in a bathroom with a hot shower running.
If you use a bowl, be careful. Hospital data from the UK showed a spike in scald burn cases during the COVID-19 pandemic, when more people were doing steam inhalation at home. Six pediatric burn cases were admitted to a single hospital in one month, compared to a yearly average of two. A commercially available facial steamer is a safer option than a bowl of boiling water that can tip over. Never let children do steam inhalation unsupervised, and keep water temperature moderate rather than at a rolling boil.
Consider an Expectorant
Guaifenesin is the active ingredient in most over-the-counter expectorants. It works by thinning the mucus in your airways so it’s easier to cough up. The standard form is taken every 4 hours as needed, while extended-release versions are taken every 12 hours. Drink plenty of water when taking it, since the medication works by drawing water into the mucus.
Guaifenesin is an expectorant, not a cough suppressant. It won’t stop you from coughing. It makes coughing more productive. If your cough is bringing up phlegm, that’s actually what you want. Suppressing a productive cough can leave mucus sitting in your lungs longer.
Honey for Cough and Phlegm
Honey is surprisingly effective, particularly for cough associated with upper respiratory infections. In a study of 300 children ages 1 to 5, honey improved cough frequency, cough severity, and sleep quality. A Cochrane review found no significant difference between honey and common over-the-counter cough medications like dextromethorphan, meaning honey performed about as well as the pharmacy options.
An Italian study of 134 children found that honey mixed with warm milk reduced cough by more than 50% in 80% of participants, compared to 87% in the group taking OTC cough medication. The difference wasn’t statistically significant. A spoonful of honey in warm water or tea gives you dual benefit: the honey itself plus the effect of the hot liquid on mucus flow. Do not give honey to children under one year old due to botulism risk.
Use Gravity to Your Advantage
Postural drainage uses body positioning to let gravity pull mucus out of specific parts of your lungs. The basic idea is simple: position yourself so the congested part of your lungs is above your airway opening, and gravity does some of the work for you.
If your chest feels congested in the front, lying on your back with a pillow under your hips (head lower than chest) can help drain those segments. If congestion is more in the back of your lungs, lying face down in a similar tilted position works better. Side-lying positions target the lateral lung segments. Stay in position for 5 to 10 minutes, breathing normally, and combine it with huff coughing afterward to clear what gravity has loosened. This is especially useful first thing in the morning, when mucus has pooled overnight.
Gargling With Salt Water
A warm salt water gargle can help clear phlegm that’s sitting in your throat, though it won’t reach mucus deeper in your chest. The salt draws moisture across the membranes of your throat, and the gargling motion physically loosens mucus from the back of your throat. Research shows that higher salt concentrations can actually increase the barrier function of mucin, so keep the solution mild: about half a teaspoon of salt in a cup of warm water. Gargle for 15 to 30 seconds and spit.
What Phlegm Color Can Tell You
Clear or white phlegm is typical of viral infections, allergies, or mild irritation. Yellow or green phlegm usually signals an infection, though the color alone can’t tell you whether it’s bacterial or viral. Many viral infections produce green phlegm, so green doesn’t automatically mean you need antibiotics.
Red, pink, or blood-tinged phlegm is worth a call to your doctor. It could be from a minor cause like burst blood vessels from forceful coughing, but it can also signal something more serious. This is especially true if you smoke. Dark brown or unusually sticky phlegm is associated with chronic lung conditions like bronchiectasis or cystic fibrosis and may indicate a flare-up that requires treatment.
For timing, bacterial infections typically resolve within 10 to 14 days even without antibiotics, though treatment can speed recovery. Viral infections can linger longer, sometimes up to three weeks. If your phlegm isn’t improving after that window, or if it’s getting worse after initially improving, that’s a sign something else may be going on.