Phlegm is a type of mucus made in your chest. You typically don’t produce noticeable amounts of phlegm unless you are sick with a cold or have some other underlying medical issue. When you cough up phlegm, it’s called sputum. You may notice different colored sputum and wonder what the colors mean.

Here’s your guide to different conditions that produce phlegm, why it might be different colors, and when you should see a doctor.

green or yellow brown white black clear red or pink
allergic rhinitis ✓
bronchitis ✓ ✓ ✓ ✓
chronic obstructive pulmonary disease (COPD) ✓
congestive heart failure ✓ ✓
cystic fibrosis ✓ ✓
fungal infection ✓
gastroesophageal reflux disease (GERD) ✓
lung abscess ✓ ✓ ✓
lung cancer ✓
pneumonia ✓ ✓ ✓ ✓
pneumoconiosis ✓ ✓
pulmonary embolism ✓
sinusitis ✓
smoking ✓
tuberculosis ✓

If you see green or yellow phlegm, it’s usually a sign that your body is fighting an infection. The color comes from white blood cells. At first, you may notice yellow phlegm that then progresses into green phlegm. The change occurs with the severity and length of the potential sickness.

Green or yellow phlegm is commonly caused by:

  • Bronchitis. This usually starts off with a dry cough and eventually some clear or white phlegm. Over time, you may start coughing up yellow and green phlegm. This is a sign that the illness may have progressed to a secondary bacterial infection. Coughing can last up to 90 days.
  • Pneumonia. This is typically a complication of another respiratory issue. With pneumonia, you may cough up phlegm that is yellow, green, or sometimes bloody. Your symptoms will vary based on the type of pneumonia you have. Cough, fever, chills, and shortness of breath are common symptoms with all types of pneumonia.
  • Sinusitis. This is also known as a sinus infection. A virus, allergies, or even bacteria can cause this condition. When bacteria cause it, you may notice yellow or green phlegm, nasal congestion, postnasal drip, and pressure in your sinus cavities.
  • Cystic fibrosis. This is a chronic lung disease where mucus builds up in the lungs. This disease often affects children and young adults. It can cause a variety of phlegm colors, from yellow to green to brown.

You may also consider this color “rusty” in appearance. The color brown often means old blood. You may see this color after your phlegm appears red or pink.

Brown phlegm is commonly caused by:

  • Bacterial pneumonia. This form of pneumonia can produce phlegm that is green-brown or rust-colored.
  • Bacterial bronchitis. This condition can produce rusty brown sputum as it progresses. Chronic bronchitis may also be a possibility. You may be more at risk of developing chronic bronchitis if you smoke or are often exposed to fumes and other irritants.
  • Cystic fibrosis. This chronic lung disease may cause rust-colored sputum.
  • Pneumoconiosis. Inhaling different dusts, like coal, asbestos, and silicosis, can cause this chronic lung disease. It can cause brown sputum.
  • Lung abscess. This is a cavity filled with pus inside your lungs. It’s usually surrounded by infected and inflamed tissue. Along with cough, night sweats, and loss of appetite, you may experience a cough that brings up brown or blood-streaked sputum. This phlegm also smells foul.

You may experience white phlegm with several health conditions.

White phlegm is commonly caused by:

  • Viral bronchitis. This condition may start off with white phlegm, indicating a viral infection. However, this can lead to a secondary bacterial infection that will produce green or yellow phlegm.
  • GERD. This chronic condition affects your digestive system. It may cause you to cough up thick, white sputum.
  • COPD. This condition causes your airways to narrow and your lungs to produce excess mucus. The combination makes it hard for your body to get oxygen. With this condition, you may experience white sputum.
  • Congestive heart failure. This occurs when your heart isn’t effectively pumping blood to the rest of your body. Fluids build up in different areas, leading to edema. Fluid collects in the lungs and may lead to an increase in white sputum. You may also experience shortness of breath.

Seek immediate medical attention if you’re having difficulty breathing.

Black sputum is also called melanoptysis. Seeing black phlegm may mean you have inhaled a high amount of something black, like coal dust. It may also mean you have a fungal infection that needs medical attention.

Black phlegm is commonly caused by:

  • Smoking. Smoking cigarettes or certain drugs like crack cocaine may lead to black sputum.
  • Pneumoconiosis. One type in particular, black lung disease, may cause black sputum. It mostly affects coal workers or anyone else who has frequent exposure to coal dust. Coughing up black sputum may also be accompanied by shortness of breath.
  • Fungal infection. A black yeast called Exophiala dermatitidis causes this infection. It’s an uncommon condition that can cause black phlegm. It more often affects people who have cystic fibrosis.

Your body produces clear mucus and phlegm on a daily basis. This phlegm is mostly filled with water, protein, antibodies, and some dissolved salts to help lubricate and moisturize your respiratory system.

An increase in clear phlegm may mean that your body is trying to flush out an irritant, like pollen, or some type of virus.

Clear phlegm is commonly caused by:

  • Allergic rhinitis. This is also called nasal allergy or sometimes hay fever. It makes your body produce more nasal mucus after exposure to allergens like pollen, grasses, and weeds. This mucus creates postnasal drip and may make you cough up clear phlegm.
  • Viral bronchitis. This is an inflammation in the bronchial tubes in your lungs. It begins with clear or white phlegm and coughing. In some cases, if a secondary bacterial infection sets it, you may find that the phlegm progress to a yellow or green color.
  • Viral pneumonia. This form of pneumonia is caused by an infection in your lungs. Early symptoms include fever, dry cough, muscle pain, and other flu-like symptoms. You may also see an increase in clear phlegm.

Blood is likely the cause of any shade of red phlegm. Pink is considered another shade of red, so it may also indicate that there is blood in your phlegm, just less of it.

Red or pink phlegm is commonly caused by:

  • Pneumonia. This lung infection may cause red phlegm as it progresses. It may also cause chills, fever, cough, and chest pain.
  • Tuberculosis. This bacterial infection can be transmitted from one person to another in close quarters. Main symptoms include coughing for more than 3 weeks, coughing up blood and red phlegm, fever, and night sweats.
  • Congestive heart failure (CHF). This happens when your heart isn’t effectively pumping blood to your body. In addition to pink or red-tinged sputum, you may also experience shortness of breath.
  • Pulmonary embolism. This happens when the pulmonary artery in your lungs becomes blocked. This blockage is often from a blood clot that travels from somewhere else in the body, like your leg. It often causes bloody or blood-streaked sputum. This condition is life threatening and may also cause shortness of breath and chest pain.
  • Lung cancer. This condition causes many respiratory symptoms, including coughing up red-tinged phlegm or even blood.

Contact your doctor if you’re producing more phlegm than normal, having intense coughing spells, or notice other symptoms like weight loss or fatigue.

The consistency of your phlegm can change due to many reasons. The scale ranges from mucoid (frothy) and mucopurulent to purulent (thick and sticky). Your phlegm may get thicker and darker as an infection progresses. It may also be thicker in the morning or if you are dehydrated.

Clear phlegm that’s associated with allergies is generally not as thick or sticky as the green sputum you see with bacterial bronchitis or the black phlegm from a fungal infection.

Moving beyond colors now: Is your phlegm frothy? Another word for this texture is “mucoid.” White and frothy phlegm may be another sign of COPD. A secondary bacterial infection may also occur, which may change the phlegm to yellow or green.

Is it both pink and frothy? This combination may mean you are experiencing congestive heart failure in a late stage. If you have this condition along with extreme shortness of breath, sweating, and chest pain, call your local emergency services immediately.

While phlegm is a normal part of the respiratory system, it’s not normal if it’s affecting your everyday life. It may be time to call your doctor if you notice it in your airways, throat, or if you start coughing it up.

If your sputum is clear, yellow, or green, you may be OK to wait a few days or even weeks before making an appointment. Still keep watch over your other symptoms to see how your illness is progressing.

If you see any shade of red, brown, or black phlegm, or are experiencing frothy sputum, make an appointment right away. This may be a sign of a more serious underlying condition.

It can be difficult to self-diagnose what type of lung issue you’re having. A doctor can perform a variety of tests, including X-rays and sputum analyses, to determine the cause.

If you’re not sure what’s causing the change in color or are experiencing other unusual symptoms, contact your doctor.

Learn more: Sputum culture »

There are times when phlegm is a reason to call your doctor right away. Some phlegm-causing conditions respond best to antibiotics, other medications, and breathing treatments. In some cases, surgery may be necessary.

Some of the conditions on this list are viral. That means they don’t respond to antibiotics. Instead, you simply need to eat well, hydrate, and rest to heal.

You can also try measures like:

  • Using a humidifier in your home. Keeping the air moist can help loosen phlegm and allow you to cough it up more easily.
  • Gargling with salt water. Mix a cup of warm water with 1/2 to 3/4 teaspoon of salt, and gargle to loosen any mucus from allergies or a sinus infection that’s affecting your throat.
  • Using eucalyptus oil. This essential oil works by loosening the mucus in your chest and can be found in products like Vicks VapoRub.
  • Taking over-the-counter expectorants. Medications like guaifenesin (Mucinex) thin your mucus so it flows more freely and you can more easily cough it up. This medication comes in formulations for adults and children.

Phlegm is produced by your respiratory system as protection for your lungs. Unless you have an underlying medical condition, you may not notice your sputum. You may only cough it up if you are sick or develop a chronic lung disease.

If you do cough it up, pay attention to its appearance. If you notice a change in color, consistency, or volume, contact your doctor to make an appointment.

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