Phlegm is naturally clear. So, if your phlegm is a different color, such as yellow or green, you may have a viral or bacterial infection. Brown, red, or black phlegm may be a sign of a more serious condition.

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.

Ongoing studies are questioning the importance of the color of phlegm and whether it is clinically relevant in all cases or only in specific scenarios. However, being aware of changes and their potential implication can help you better understand when it is necessary to seek help.

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 yellowbrownwhiteblackclearred or pink
allergic rhinitis


chronic obstructive pulmonary disease (COPD)

congestive heart failure

cystic fibrosis

fungal infection

gastroesophageal reflux disease (GERD)

lung abscess

lung cancer



pulmonary embolism




If you see green or yellow phlegm, it’s usually a sign that your body is fighting an infection such as pneumonia. 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:

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:

You may experience white phlegm with several health conditions.

White phlegm is commonly caused by:

Seek immediate medical attention if you’re having difficulty breathing or feel a tightness in your chest alongside cloudy phlegm production, this may indicate heart failure or other serious complications.

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:

Your body produces clear mucus and phlegm daily. This phlegm mostly contains 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
  • viral bronchitis
  • viral pneumonia

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:

Contact your doctor if you’re producing more phlegm than normal, have 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, changing 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 or throat or start coughing it up.

If your sputum is clear, yellow, or green, it may be safe to wait a few days or 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 immediately. This may be a sign of a more serious underlying condition.

There are times when phlegm is a reason to call your doctor immediately. 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 must 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 teaspoons of salt, and gargle to loosen any mucus from allergies or a sinus infection 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.

Do you need antibiotics to get rid of green phlegm?

Green phlegm is a sign that the body is fighting an infection. In cases of viral infection, antibiotics will not have an effect. Doctors may prescribe antibiotics to treat a severe bacterial infection if the condition does not improve independently.

Is green phlegm bacterial or viral?

Your phlegm may appear green due to either bacterial or viral infection.

What does it mean when your phlegm is green?

Having green phlegm typically means your body is fighting an infection. Causes can include bronchitis, pneumonia, sinusitis, or cystic fibrosis.

Do you get green phlegm with COVID-19?

Green phlegm can occur with viral infections like COVID-19 and bronchitis and also with bacterial infections. The only way to determine if your green phlegm is due to COVID-19 is to get tested.

Your respiratory system produces phlegm 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 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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