Look, it's not gross at all to take a peek inside your tissue after blowing your nose or sneezing. You never really know what's going to come out of your nose, especially if you have allergies. And experts say you can tell a lot about your health by examining your mucus. However, the idea that you can diagnose a cold or virus just by looking at your snot is actually a myth.
Your body is constantly making mucus, about one liter or more of the slimy stuff a day, says Neil L. Kao, MD, FAAAAI, an allergist in Greenville, SC. Normal mucus is made up of mostly water, with some proteins mixed in there that give it its texture, he says. These proteins and other substances that get stuck in your mucus can also change its color.
When you have a cold, your mucus might change color, but "mucus from an infection can look like just about anything," says Derrick R. Ward, MD, an allergist in Kansas City, "There's no way to differentiate between a viral or bacteria infection based on mucus color." Instead of focusing solely on the shade of your boogers, it's more worthwhile to pay attention to the amount of mucus you're making as well as any other symptoms of a cold, such as a headache or a sore throat, if you're trying to tell if you're sick.
That said, given the range of colors that your snot can be, ahead are some ones to look out for next time you reach for a tissue.
Normally, healthy mucus is clear, but that doesn't mean that clear mucus is always 100% healthy, Dr. Kao says. For example, if you have a sinus infection or seasonal allergies, your mucus will still be clear, he says. If you notice an uptick in clear mucus, the key is keeping track of other symptoms that could signal the underlying cause, such as a headache, itchy eyes, or a sore throat.
Gnarly green mucus can be a little jarring to see in your tissue. When you have an infection or inflammation, your body sends white blood cells to fight it, Dr. Kao explains. "These white blood cells have an enzyme that's actually greenish," he says. So, the greener your snot, the more white blood cells you have trying to get rid of an infection. "You'd have to examine the mucus under the microscope" to tell what's going on, he says.
Orange to brown
Thick, dried mucus can often turn an orange-to-brown hue, Dr. Kao says. "It's annoying, because it's not going to come out easily," and it may make it harder to breathe from your nose, but it's not necessarily cause for concern, he says. Using a neti pot or saline solution is one way to get rid of it, he says. However, if you're someone with seasonal allergies, then your mucus can turn discolored red or brown as well, Dr. Ward says.
White or opaque
This is usually NBD, and can be a sign of your mucus thickening and slowing down, due to inflammation or irritation of the nasal passages, according to the Cleveland Clinic. This can happen because you were around smoke, you have a virus, or you have allergies, Dr. Kao says.
This is usually NBD, and can be a sign of your mucus thickening and slowing down, due to inflammation or irritation of the nasal passages, according to the Cleveland Clinic. This can happen because you were around smoke, you have a virus, or you have allergies, Dr. Kao says. (Red mucus, of course, could indicate a bloody nose too.)