THE SEMI-COMPLETE USER'S GUIDE TO...THE SINUSES

FOR AS LONG as sinuses have been around, aka forever, there's been a ton that scientists haven't figured out about them.

-  KEVIN DUPZYK

We're aware that our sinuses help our noses work better, keep our skulls lighter, and act as "crumple zones" that cushion impacts to the head. But, among other things, why must they drain through the nasal cavity, which is the root of many problems? "I don't know that we actually know the answer," says Jean Kim, M.D.,Ph.D., a professor of otolaryngology at Johns Hopkins Medicine.

Dr. Kim and fellow experts do know that sinus issues are getting worse, and they have a few guesses as to why. For one, sterile modern life exposes us to fewer irritants, giving our bodies fewer chances to learn to deal with them. Climate change is making allergy seasons worse and irritants like wildfire smoke more common. Obesity can pressurize parts of the head that interface with the sinuses.

But that still leaves perhaps the most confusing thing of all: Often we think we have "sinus issues," but they're something else entirely. So how do you fix them? With a quick anatomy lesson, some insight on root causes, and various pros who can help.

WHAT'S IN THERE, ANYWAY?

"Sinus" is a generic term that means "cavity" or "hollow space." When you complain about "sinus issues," you're referring to what happens in the paranasal sinuses, four pairs of spaces that drain through your nasal cavity and down the back of your throat. Knowing what's there helps you take care of it better.

THESE ARE YOUR SINUSES: Below is a straight-on view-the image on the left is from the side and they help filter, warm, and moisturize air bound for the lungs.

Cilia and mucosa LINE THE SINUS SPACES. The mucosa produce mucus, which traps potentially problematic particles like dust mites and microbes. The cilia-tiny hairs-move mucus toward the nasal cavity.