What your doctor calls phlegm becomes mucus in polite conversation, and snot for those who are plagued by too much of it. Whatever you call it, phlegm is something your body manufactures on overdrive when you have a cold or the flu. Sinusitis, bronchitis and pneumonia can also give you an ample supply of the stuff, as can hay fever and other allergies. Although the color of your mucus may have meaning, it’s usually not enough to determine if you need to call in sick.
If you’re like most people, your opinion of phlegm is stuck somewhere near “gross.” But phlegm is essential to good health. The fluid, sticky substance helps protect against illness by trapping and expelling foreign invaders; it also keeps your nasal tissues nice and moist. Normal phlegm is clear. Although it’s mostly water, it also contains proteins, antibodies and dissolved salts. When you’re congested, your phlegm is more likely to be white. That’s because inflamed nasal tissues are slowing its flow, causing it to thicken and become cloudy. Yellow phlegm may indicate that you have a cold or other infection, and it’s progressing. Your body uses phlegm to expel white blood cells once they’re spent; phlegm’s yellow tinge comes from having a higher concentration of these infection-fighting cells.
Having green phlegm may mean that your immune system is really fighting back. According to Cleveland Clinic, phlegm turns green when it has a very high concentration of dead white blood cells in it, which generally means that your body is in the throes of battling a big infection. When you don’t blow your nose for a while, your phlegm becomes even more concentrated; that’s why it may be a deeper shade of green in the morning, when you first get up. Although it was once generally accepted that green phlegm indicated a bacterial infection — meaning it would require an antibiotic to defeat — this has since been proven a myth. As Harvard Health Publications points out, your body can produce green phlegm when you’re fighting a viral infection, too; even seasonal allergies have been known to generate green mucus.
If green phlegm is your only real symptom — that is, if you have green mucus, but you don’t have a fever or sore throat, you aren’t sneezing or coughing frequently, and you don’t have any sinus pressure — chances are, you’re not going to spread too many germs by heading to work. But when you have a fever, or your body aches, or you just don’t feel well, it’s probably in your best interest, as well as your co-workers’, to stay home and rest. You can generally return to work once you’ve been fever-free for 24 hours, especially if your other symptoms seem to be improving. If your symptoms don’t improve much after 10 days, or if they get worse after a week, consider seeing your doctor.
Even if you don’t necessarily feel congested or otherwise unwell, there are still things you can do to support your body’s effort when it’s overcoming an infection.
- Apply a warm, moist cloth to your face several times a day to help loosen phlegm. Running a humidifier will have a similar effect.
- Drink plenty of liquids to thin out your phlegm. This makes it easier to expel, which can help you clear the infection more quickly.
- If you’re congested, a gentle saline nasal spray may help you get through the day. An over-the-counter decongestant can help you breathe easier at night, so you can get the rest you need.