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.
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.
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.
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. 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.
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.
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.
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.