Skip to Accessibility Tools Skip to Content Skip to Footer

Asthma Lexicon: The Color Of Sputum

So, you are producing sputum. When you do this, you should look at it. I know, it’s gross! Still, the color of your sputum can help your doctor diagnose you. It can help your doctor determine what is wrong with you.

Here’s what to know.

Clear. It’s the normal color of mucus.3

White. It may indicate airway inflammation. It’s white because it contains white blood cells. These cells are recruited to the lungs as part of the asthma response. Asthma is an abnormal immune response. This means white blood cells are abnormally recruited to airways, and not in response to an infection. The mucus probably includes eosinophils. It may also include neutrophils. So, white usually means there is no infection. It’s a common color of asthma sputum.4-6

Thick white. This may be the color of sputum when you have GERD. It’s the color of mucus plus airway cells plus white blood cells plus regurgitated stomach contents. It may be frothy. It’s often the only symptom of GERD. Another sign of GERD is a cough at night, or while lying down. Keep in mind that GERD may be an asthma trigger.6

Colorful sputum. This is any color other than clear or white, such as yellow, green, or brown. It’s an indicator that germs (bacteria or virus) are in present in the sputum. Colorful sputum shows how long a bacteria is present in airways. It generally consists of the bacteria plus a combination of cells, such as from surrounding tissue, white blood cells, and red blood cells.6

Green. It’s a sign that bacteria and pus is present in the sputum. Pneumonia is caused by bacteria. It causes pus build-up in the alveoli. So, it may produce green sputum. The green color may also be from nasal drainage. So, it can also be a sign of an upper airway infection, such as sinusitis. It can also be an indicator that an infection has been around for a while. So, it may also indicate conditions such as chronic bronchitis, bronchiectasis, and cystic fibrosis.6-7

Yellow. It’s a common color in people with chronic bronchitis (COPD).  It tends to be thick. It can indicate a bacterial infection.3-5

Dark Yellow. It may indicate a bacterial infection.

Light Yellow. It may indicate a viral infection. Viral infections may produce clear secretions. If they produce a color, it tends to be a lighter color yellow-ish color.

Brown. It may indicate an infection such as pneumonia. It may also indicate an infection that has been around for a while. This may occur in people living with COPD, who tend to be more prone to lung infections.7 Brown may also indicate the color of sputum in those who smoke.

Rust. It may also indicate an infection. It may indicate pneumonia.2,3,7

Brown Plugs. This may indicate Allergic Bronchopulmonary Aspergillosis.4

Pink. This may indicate the breakdown of eosinophils. So, it may be seen in people with allergies.6

Red. It usually indicated the presence of red blood cells. It could be a sign of an infection, such as pneumococcal pneumonia. It may also indicate other conditions not related to asthma.

Gray/ Black. It’s most likely to be seen in people who smoke. So, I won’t delve into it here.6

What to make of this?

If your sputum is colorful, your doctor may want a sample. You will likely be asked to spit a sample into a cup. It must be a sample from deep inside your lungs. It can then be sent to a laboratory. Tests can determine what cells are present in it. Tests can also determine what germs are in it if any. This can help your doctor determine how best to treat you.

  1. Tortora, Gerald J., Bryan Derrickson, “Principles Of Anatomy And Physiology,” 15th edition, 2017, Wiley, pages  40, 78-79, 104, 111, 113, 115, 135
  2. Harrison, TR, et al., editors, “Harrison’s Principles And Practice Of Medicine,” 19 Edition, 2015, McGraw    pages 243-244
  3. Shelledy, David C., J. I. Peters, editors, “Respiratory Care: Patient Assessment And Care Plan Development,” 2016, Jones & Bartlett Learning, page 96
  4. Andreoli, et al., editors, “Andreoli And Carpenters Cecil’s Essentials of Medicine,” 8th edition, 2010, Saunders Elsevier, page 193
  5. Scanlan, et al., editors, “Respiratory Therapist Exam Review Guide,” 2010, Jones & Bartlett Publishers, page 69
  6. Koeppen, Bruce M., Bruce A. Stanton, editors, “Berne & Leve Physiology,” 7th edition, 2018, Elsevier, page 500
  7. Kovalyova, Olga, Tetyana Ashcheulova, editors, “Propedeutics To Internal Medicine,” part 1, 2nd edition, 2011, Vinny Nova Knyha Publishers,  page 123-125


  • Shellzoo
    12 months ago

    My sputum is the color of the rainbow LOL! Actually it is mostly frothy white and sometimes yellow tinged. I did not know that the white sputum was typical for asthma. I still have this deep down hope that the doctor made a mistake and I don’t have asthma and then I read that white sputum is typical for asthma………

  • Poll