Why Are You Coughing Up Phlegm? Causes & What to Do

Key takeaways:

• Coughing is one of the most common complaints that prompt visits to healthcare providers.
• There are many possible causes of coughing up phlegm, and various treatments are available.
• Coughing up phlegm can be a natural reflex, but it may also indicate an underlying medical condition such as an infection, lung or heart condition, or even a malignancy.

Coughing is the most common reason people visit their healthcare providers. There are many reasons why you might be coughing up phlegm, and not all of them indicate a medical problem that requires attention from your doctor. The most frequent cause is viral infections, such as the common cold. However, coughing up phlegm can also be associated with sinus infections, asthma, allergies, congestive heart failure, or various lung and gastrointestinal problems.

Coughing is part of your body's immune response that aims to remove bacteria, viruses, debris, and other potential foreign invaders. A cough that lasts longer than three weeks is considered chronic and may indicate an ongoing issue.

Coughing up phlegm is generally not serious. However, the importance of your symptoms greatly depends on the underlying cause. In some cases, you may need to visit your doctor.

Definition of phlegm

Mucus is a normal substance everyone produces. Your nose and sinuses create approximately one liter of mucus per day, which you typically swallow.

Phlegm, or sputum, is the mucus of the lungs and airways. The presence of phlegm usually indicates that your body is fighting an infection, disease, or inflammation. Phlegm is a gel-like, water-based substance that contains proteins, lipids, and debris. Its color varies depending on the contents.

What phlegm says about your health

Coughing or clearing your throat is natural when you are dealing with too much phlegm. Many people eliminate phlegm by either swallowing it or spitting it out. Excess phlegm usually indicates that your body is responding to an infection or illness. Other times, it may be a reaction to air pollution, smoke, or harmful chemicals.

Abnormal vs. normal phlegm

Excess phlegm can provide clues about a recent infection but may also signal an underlying health issue. It may be difficult to determine whether you are dealing with a normal or abnormal amount of phlegm.

Common causes of phlegm

Various health conditions may cause you to cough up phlegm. The characteristics of the phlegm and any other signs or symptoms can help determine the best course of action to improve your health.

Infections

The most common cause of coughing up phlegm is a viral infection, such as the common cold, flu, or COVID-19. Viruses and, in rare cases, fungi can also cause infection. Bacterial infections may affect the sinuses, airways, and lungs. Postnasal drainage, chest congestion, and nasal congestion are common causes of coughing up phlegm. The most serious infections are pneumonia and whooping cough.

Allergies

Environmental allergies to pollen, dust, mold, and other allergens can lead to coughing up phlegm. Typically, these allergies worsen during the spring and fall, especially in areas with high concentrations of allergens. The impact of allergies can vary from person to person. You might experience allergic rhinitis, which is inflammation of the nasal passages. Coughing up phlegm is often a result of postnasal drip.

Asthma

Asthma is similar to allergies in that it involves a complex and overactive immune response. Environmental allergens can lead to inflammation, difficulty breathing, and heightened sensitivity in the airways. Coughing up phlegm often occurs due to increased mucus production and the narrowing of the airways.

Lung and heart diseases

More serious possible causes for coughing up phlegm include lung and heart diseases, such as:

• Chronic obstructive pulmonary disease (COPD)
• Emphysema
• Bronchiectasis
• Interstitial lung disease due to scarring and hardening of lung tissue. It may result from exposure to:
  • Asbestos
  • Silicone
  • Coal dust
  • Radiation
  • Heavy metals
• Autoimmune diseases
  • Rheumatoid arthritis
  • Scleroderma
  • Dermatomyositis
  • Polymyositis
  • Mixed connective tissue disease
  • Sjogren's syndrome
  • Sarcoidosis
• Tuberculosis
• Neuromuscular disorders
• Chronic aspiration
• Congestive heart failure

Gastroesophageal reflux (GERD)

Gastroesophageal reflux disease (GERD) accounts for over one-third of chronic coughs. GERD occurs when stomach acid rises into the esophagus and irritates the throat. This irritation may lead to coughing up phlegm. Many individuals notice that their coughing and phlegm symptoms worsen when lying down.

Environmental and lifestyle factors

Some causes of coughing up phlegm may be due to certain environmental circumstances or lifestyle habits.

Situations include:

• Smoking
• Alcohol or caffeine consumption
• Dehydration
• Dry, desert environments
• Excessive exercise

Common phlegm colors

Many people try to understand what the color and characteristics of phlegm may indicate about their health. While the color of phlegm can provide some clues about possible causes, there is often significant overlap in diagnoses.

Here are some common conditions associated with particular colors of phlegm:

• Clear: Possible normal reaction to environmental allergens or viral infection.
• Yellow: Possible early stages of infection.
• Green: Possible sign of a persistent infection that requires medical attention.
• White: Possible sign of longstanding heart or lung disease such as COPD or congestive heart failure. It might also indicate GERD.
• Black: Could be a sign of smoke inhalation, smoking cigarettes, exposure to coal or coal dust, or, rarely, a fungal infection.
• Pink: Might indicate minor bleeding or irritation in the airways or lungs. It may come and go.
• Red: Possible sign of more severe bleeding and irritation in the airways and lungs. It could indicate pneumonia, congestive heart failure, tuberculosis, interstitial lung disease, or, rarely, pulmonary embolism or lung cancer.

How to stop coughing up excess phlegm or abnormal phlegm

The treatment for coughing up phlegm depends on the accompanying signs and symptoms. Several home remedies may be effective. However, seeking medical attention is important if you have persistent or unusual phlegm and are concerned about your health.

Home remedies

Coughing up phlegm may improve with various at-home remedies, including:

• Humidification
  • Hot steamy showers
  • Humidifiers
• Drinking plenty of fluids
  • Water is best
  • Hot liquids like tea with honey and soups may help
• Gargling with warm salt water. Mix ¼ to ½ teaspoons of salt with eight ounces of water and gargle to loosen phlegm and prevent coughing.
• Over-the-counter medicines
  • Expectorants
  • Cough suppressants
  • Antihistamines
  • Decongestants
  • Ibuprofen and Tylenol (acetaminophen), which may help decrease inflammation in your lungs and airways and help you stop coughing up phlegm.
  • Eucalyptus oil, which is most commonly found in salves and creams such as Vicks VapoRub.

Antibiotics, antivirals, and antifungal medicines

If you are coughing up phlegm and decide to visit your healthcare provider, you may need prescription medication. Your treatment of phlegm coughing will be focused on symptom relief. Antibiotics may be necessary if there are signs of a bacterial infection.

However, healthcare providers may be cautious about prescribing antibiotics, antivirals, or antifungal medications unless evidence supports a definitive diagnosis. In some cases, antibiotics may help reduce phlegm production due to their anti-inflammatory effects.

Other prescription medicines

Other medications may help reduce coughing and phlegm production. A short course of corticosteroids, which are synthetic versions of hormones that your body naturally produces to combat inflammation and infection, might do the trick. They work quickly to relieve pain and reduce coughing and phlegm. However, their effects may be temporary, and overuse of corticosteroids should be avoided.

Other medications that may be prescribed include inhalers, anti-reflux medications, and stronger cough suppressants or pain relievers. One of the most effective cough suppressants is codeine, which should be used with caution.

How to prevent excess phlegm or abnormal phlegm

Many strategies for preventing excess or abnormal phlegm are similar to those for treating it. Sometimes, the best way to prevent coughing up phlegm is to stop the overproduction of phlegm.

Hydrate

Dehydration and dryness in the airways and lungs can lead to excessive phlegm production and coughing. Drinking plenty of fluids, primarily water, along with hot teas or other warm liquids, is highly effective in preventing phlegm buildup. Avoid sugary or milk-based drinks, as they can contribute to mucus overproduction and thicken phlegm.

Humidify the air

Hot, steamy showers may help prevent coughing up phlegm. The humidification and heat will expand your airways and help thin excessive mucus. Humidifiers also help, but they must be properly maintained so they don’t collect mold or bacteria.

Nasal saline spray and flushes

Nasal saline spray and flushes help decrease mucus and thin phlegm. They also stop postnasal drip, which may cause coughing up phlegm. Nasal saline is not addictive and cannot be overused.

Gargling with salt water

Gargling with salt water may help prevent thick phlegm and cough. Salt water gargles can also decrease inflammation in the throat and airways, soothe irritation, and provide direct humidification.

When you should see a doctor about phlegm

Even with your best efforts to prevent or treat coughing up phlegm, seeking medical attention might be necessary.

You should see a doctor if:

• Your cough lasts more than several weeks
• You have unexplained weight loss
• You are a tobacco smoker
• You have been exposed to potential environmental chemicals or toxins
• You are coughing up blood
• You have a high fever (101 degrees Fahrenheit or higher)
• You experience hoarseness, excessive perspiration, or acid reflux
• You have a neck mass or drainage
• You’re experiencing headaches

You should go to the emergency room if:

• You have chest or abdominal pain
• Your heartbeat is irregular
• You’ve lost your voice
• You have shortness of breath
• You’re making unusual sounds while breathing
• You’re bleeding from the mouth or coughing up blood
• You have fainted or passed out
• You are vomiting blood

Questions to ask your doctor about phlegm

• What can I do to stop coughing?
• What tests or X-rays can be done to find out why I am coughing up phlegm?
• Do I need antibiotics to stop coughing up phlegm?
• Do I have a serious illness like lung cancer?

How a doctor may help treat phlegm

If you frequently cough up phlegm, seek medical advice. Your doctor may recommend only symptomatic treatment, but you might need additional testing.

Antibiotics

Your doctor may prescribe antibiotics if they suspect an infection. Make sure you tell your doctor about any medication allergies. The most common antibiotics used for coughing up phlegm include:

• Amoxicillin clavulanate (Augmentin)
• Azithromycin
• Cefuroxime
• Clindamycin
• Doxycycline
• Levofloxacin
• Moxifloxacin

Inhaled medicines

Inhaled medications such as albuterol and ipratropium bromide are often delivered through nebulizer solutions. Your doctor may recommend that you purchase a nebulizer machine, which you will use to inhale the medicine. These medications create a mist that helps open or widen your airways. This usually improves breathing and may reduce coughing up phlegm.

Alternative medicines

Your doctor may diagnose you with a neurogenic cough, which means that your cough is caused by unidentified irritation or inflammation. This condition may also suggest that you have acid reflux, which could be causing you to cough up phlegm. The vast majority of people who cough up phlegm due to acid reflux do not have heartburn, and coughing is their only symptom.

Your doctor might also prescribe atypical medications such as tramadol or gabapentin. Tramadol is a pain medication that can help reduce coughing. Gabapentin, primarily used for seizure control, is also known to be effective in managing chronic cough and phlegm production.

Frequently asked questions: phlegm

You may have specific questions about coughing up phlegm, as there are many possible causes and treatment methods.

Should you spit out phlegm?

Clearing phlegm from your throat or airways can help reduce coughing. It aids in removing allergens, irritants, and potential infections from your lungs and airways.

If you must spit out phlegm, be sure to use a tissue or napkin and wash your hands afterward. Swallowing phlegm after coughing is not harmful. In fact, most of us swallow phlegm daily as it naturally drains from the back of our nose and throat.

Does coughing up phlegm while sick mean you’re getting better?

Coughing up phlegm indicates that you are clearing out infections or irritants from your lungs and airways. However, if you cannot cough up phlegm, the secretions may lead to airway blockages and increase the risk of infection, which is unhealthy. Coughing up phlegm while you are sick does not necessarily mean you have recovered; you may still be ill or contagious.

What’s the difference between phlegm and mucus?

There is no significant difference between phlegm and mucus apart from their contextual meanings. Typically, people use the term "mucus" to refer to the normal, clear fluid that can come from our nose or throat. In contrast, "phlegm" may indicate a health condition. Phlegm often suggests the presence of infection or inflammation and implies that our body is fighting off an invader, which could be smoke, chemicals, or toxins.

Last word on coughing up phlegm

Most causes of coughing up phlegm are not serious. It rarely indicates underlying issues such as infections, lung or heart problems, neurological diseases, or gastroesophageal reflux. It is important to seek medical attention if coughing up phlegm persists or is accompanied by other concerning symptoms, such as a high fever, difficulty breathing, or an irregular heartbeat.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Pallabi Sanyal-Dey, MD.

Sources

Boulet, Louis-Philippe, and Julie Turmel. “Cough in exercise and athletes.” Pulmonary Pharmacology & Therapeutics vol. 55 (2019): 67-74. doi:10.1016/j.pupt.2019.02.003

Birring, Surinder S, et al. “Treatment of Interstitial Lung Disease Associated Cough: CHEST Guideline and Expert Panel Report.” Chest vol. 154,4 (2018): 904-917. doi:10.1016/j.chest.2018.06.038

Pourmand, Ali, et al. “Pulmonary Embolism Among Patients With Acute Exacerbation Of Chronic Obstructive Pulmonary Disease: Implications For Emergency Medicine.” The Journal of Emergency Medicine vol. 55,3 (2018): 339-346. doi:10.1016/j.jemermed.2018.05.026

Randel, Amber. “ACCP Releases Guideline for the Treatment of Unexplained Chronic Cough.” American family physician vol. 93,11 (2016): 950.