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The Truth About Mucus

Call it snot, call it mucus, call it a booger -- but don't underestimate what it does for you.

Why Does My Mucus Change Color?

If you've ever stopped to look at the contents of the tissue after you've blown your nose, you may have noticed that your mucus isn't always perfectly clear. It may be yellow, green, or have a reddish or brownish tinge to it. What do those colors mean?

You might have heard that yellow or green mucus is a clear sign that you have an infection, but despite that common misperception, the yellow or green hue isn't due to bacteria.

When you have a cold, your immune system sends white blood cells called neutrophils rushing to the area. These cells contain a greenish-colored enzyme, and in large numbers they can turn the mucus the same color.

But "you can have perfectly clear mucus and have a terrible ear and sinus infection," Kao says. If you do have an infection, you'll likely also have other symptoms, such as congestion, fever, and pressure in your face, overlying the sinuses, Johns says.

Multi-hued mucus also relates to concentration of the mucus. Thick, gooey mucus is often greenish, Kao says.  

Mucus can also contain tinges of reddish or brownish blood, especially if your nose gets dried out or irritated from too much rubbing, blowing, or picking. Most of the blood comes from the area right inside the nostril, which is where most of the blood vessels in the nose are located. A small amount of blood in your mucus isn't anything to worry about, but if you're seeing large volumes of it, call your doctor.

How Can I Get Rid of Mucus?

People with chronic sinus problems who are constantly blowing their noses understandably want the goo gone. Over-the-counter antihistamines and decongestants are one way to do this. Decongestants cause the blood vessels in the lining of the nose to narrow, reducing blood flow to the area, so you're less congested and you produce less mucus.

Decongestants are fine for when you can't breathe due to a cold, but they're not so good for thick mucus in general. "The reason is the decongestants dry you up and they make the mucus thick, and often the opposite effect happens because you feel like you have thick mucus," Johns explains. So you take more decongestants and get into a vicious mucus-producing cycle. Decongestants also have side effects, which include dizziness, nervousness, and high blood pressure.

Antihistamines block or limit the action of histamines, those substances triggered by allergic reactions that cause the tissue in the nose to swell up and release more, thinner mucus (a runny nose). The main side effect of older antihistamines is drowsiness. They also can cause dry mouth, dizziness, and headache.

You can also thin out the mucus with guaifenesin, a type of medicine called an expectorant. Thinner mucus is easier to get out of the body. Possible side effects of guaifenesin are dizziness, headache, nausea, and vomiting.

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