Runny Nose Driving You Nuts? Here Are Five Things You Need To Know About Mucus

Mucus ranks high on the gross-out scale. But it actually plays a very important role in your body, helping to protect the linings of areas like your nasal passages from drying out and protecting you from a host of foreign invaders. “Our bodies make mucus to flush out the bad stuff,” explains Scott Renshaw, M.D., a family medicine practitioner at Indiana University Health. “If something potentially dangerous enters your system—whether that’s an allergen or bacteria— mucus helps get rid of it quickly.”  Here’s what else you should know about snot.

Mucus isn’t just inside your nose and throat. Mucus membranes go throughout your body, from your nasal passages to your GI tract to your cervix. It’s role in all of these body parts is fairly similar—to lubricate the linings of key tissues and help the immune system by filtering out invading pathogens.

It changes color. But what the color means isn’t always so simple. “Color isn’t a diagnostic tool—a greenish tinge doesn’t always signify an infection and clear fluid isn’t necessarily just allergies,” says Dr. Renshaw. The change of color from clear to yellow or green to even a brownish red can be due to the presence of bacteria, but that’s not always the case. White blood cells called neutrophils, which are mustered to areas where there is an infection, can turn mucus a greenish yellow when present in large numbers. Mucus that’s highly concentrated also tends to turn a greenish hue. And if your nasal passages get dried out or irritated, tinges of red or brown blood can also appear in the mucus. Small amounts of blood are normal but if you’re seeing a large amount, consult your doctor.

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There’s also a wide variation in consistency. If your nose is running like a faucet thanks to allergies or a cold, your body is probably doing its best to flush out invading forces like allergens or viruses. Thick mucus can occur from dry air, dehydration and smoking, as well as an infection. 

Drink more water to clear things up. It’s important to stay hydrated when you are fighting a cold or other illness, says Dr. Renshaw. All that fluid can help, since it will thin out the mucus, making it easier for your body to get rid of it.

Be careful of taking too many decongestants. If you want to clear up a cold, a decongestant can help cause the blood vessels inside the nose to narrow, which in turn means less mucus is produced.  But too much of the medication can make the nasal passages too dry, and actually thicken the existing mucus.  

-- By Alyssa Shaffer