Mucus vs. Mucous vs. Mucosa

mucus mucous mucosa

I often see ‘mucus’ and ‘mucous’ used incorrectly, so I thought I'd try to explain the difference here. (Yes, I'm a geek…)

Mucus – Noun – A viscous, slimy mixture of mucins, water, electrolytes, epithelial cells, and leukocytes that is secreted by glands lining the nasal, esphageal, and other body cavities and serves to primarily protect and lubricate surfaces. Example: Whenever I'm around cats, my nose produces more mucus.

Mucous – Adjective – pertaining to, consisting of, or resembling mucus. Example: During cold, dry months, I often use Ayr Saline Mist to rehydrate the mucous membrane in my nose.

Mucosa – Noun – another term for mucous membrane; a membrane lining all body passages that communicate with the air, such as the respiratory and alimentary tracts, and having cells and associated glands that secrete mucus. The plural is ‘mucosae.’ Example: Pollen makes my nasal mucosa feel itchy.


Depsite its bad reputation, mucus plays an important role within your immune system. It traps inhaled particles like allergens. However, the production of too much mucus is unpleasant.

Mucinex is an OTC medication that loosens and thins out mucus to relieve nasal and chest congestion.

9 thoughts on “Mucus vs. Mucous vs. Mucosa

  1. Naveed Hussain December 2, 2012 / 1:34 am

    Excellent illustration!

  2. Suzanne Skillman November 26, 2013 / 1:19 pm

    Thank you, this was very helpful!

  3. TheFeels January 3, 2015 / 10:05 pm

    Thank you.

  4. KevvyG September 3, 2013 / 8:13 am

    Though the spelling is different, the English pronounciation of mucus and mucous is the same. You are correct in noting the difference, but this is only when you pronounce it with the language from where the word originates – Latin.

  5. Smithd7 March 29, 2014 / 3:46 pm

    Very nice!

  6. Zaria Taylor March 19, 2014 / 2:54 pm

    This was very helpful. Thanks!
    P.S. I'm a geek too 🙂

  7. Max, RN September 16, 2012 / 9:55 pm

    NICE explanation!
    Thank you!

  8. Barry Longden September 2, 2013 / 8:15 am

    Is it true that the correct pronunciation of mucus as opposed to mucous is muck us” as we were told in A level Biology many years ago. “

  9. xkut October 27, 2015 / 3:19 am

    Oh my goodness! Amazing article dude! Thank you,
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