5 Fun Facts About Boogers

Boogers start out inside the nose as mucus, which is mostly water combined with protein, salt and a few chemicals. Mucus is produced by tissues not just in the nose, but in the mouth, sinuses, throat and gastrointestinal tract. It has a slimy, sticky consistency that traps potentially harmful substances in the environment, such as pollen, viruses and germs.

The nose and throat produce about a quart or more of mucus a day. Most of it mixes with saliva and is swallowed, but some stay in the nose.

In addition to keeping the tissues beneath it from drying out, mucus helps catch viruses and other harmful particles and stop them from getting into your airways. Tiny hairs inside the nose called cilia move the mucus down toward the nostrils. When you sneeze or blow your nose, you blow out the mucus. If mucus remains in the nose and starts to dry out, it becomes dried nasal mucus or a booger.

“Mucus helps flush out substances like dirt, dust or bacteria before they can get into the lungs and cause irritation or breathing problems,” says Olga Rose, MD, a pediatrician at Scripps Clinic Rancho Bernardo. “It can also help keep you from inhaling viruses that can make you sick.”

Mucus is usually clear. It tends to turn whitish when it dries, but depending on what comes into contact with it, boogers may have different colors. Here’s a quick guide to what the colors may indicate:

• Yellow or green may indicate infection, but not always. These colors are not caused by bacteria; rather, white blood cells contain a substance that adds a yellow or green tinge to mucus. If your body is fighting an infection, you may produce more white blood cells. However, you always have some white blood cells, so your boogers may be yellow or green even if you aren’t sick. (Conversely, you can be sick and still have clear mucus.) If there is an infection, you will likely have other symptoms such as congestion, sinus pressure or headache.

• Red or brownish boogers often result from tiny amounts of blood mixing with mucus. This can happen when small blood vessels lining the nose break, often from sneezing, rubbing your nose or dry nasal tissues. It’s nothing to worry about unless it happens often or there is a lot of blood; in either case, call your doctor.

• Black boogers are usually caused by dirt in your nose mixing with mucus.

It can be tempting to pry boogers out of the nose, especially for children, but it isn’t a good idea. Boogers can carry bacteria and viruses, which then get spread from your hands to whatever you touch. It also works the other way — germs on your hands can spread to your nose.

Moreover, picking can irritate the delicate tissues in your nose and make them more susceptible to infection.

Instead of picking, gently blow your nose. You can also try a saline nasal rinse with distilled water to rinse your nasal passages.

Some kids like to eat their boogers. It’s not something you want to see, but should you be concerned if it happens?

“Eating boogers is something we try to discourage,” says Dr. Rose. “It’s probably not harmful, but your body is getting rid of them for a reason, so it’s best to let nature take its course.”

If excessive boogers are a problem for your kids (or you), try increasing water intake. Staying hydrated can keep mucus thinner and easier to manage.