http://mmajunkie.com During this past weekend’s UFC 112 event in the Middle East, UFC broadcaster Joe Rogan suggested headliner Demian Maia’s badly swollen eye could have been the result of the fighter blowing his nose between round.

But is this longtime combat-sports belief based in any reality?

In his latest installment of “Ask the Fight Doc,” MMAjunkie.com medical columnist Dr. Johnny Benjamin discusses Valsalva maneuvers and what MMA fighters, fighter pilots and even a bathroom user have in common.

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Hey Doc – During Saturday’s UFC 112 event, we heard Joe Rogan talking about the eye swelling of a fighter increasing and suspected it was due to the fighter blowing his nose. I’ve heard this happened during a boxing match, too, which George Forman referred to as the “cardinal rule” to never blow your nose between rounds. What causes this? Thanks – Maj Insux



Cool question! Nothing controversial here; just basic anatomy and physiology stuff.

For those who didn’t see it, Maj is talking about UFC 112’s main event between UFC middleweight champ Anderson Silva and challenger Demian Maia. Throughout the fight, Maia’s face got bloodier and more bruised, but after apparently blowing his nose after the fourth round, the left side of his face massively swelled and forced his eye shut.

As with all fighters, Maia’s eye socket and surrounding tissues have a great deal of very vascular fat to cushion and protect the eyeball. After a fighter’s eye and the face around it have been properly tenderized by a four- to five-ounce MMA glove, the blood vessels – especially the veins – are damaged. Some of the veins are completely torn and some are just leaky.

This vascular injury and direct trauma to the soft tissue causes the puffiness, swelling and the very familiar “mouse” under the eye.

The acts of blowing your nose, grunting, straining during exercise (commonly lifting weights), pushing for a bowel movement, etc. increases venous blood pressure. This physiological event is called a Valsalva maneuver.

It is the same technique that military fighter pilots utilize to increase their blood pressure in an attempt to maintain adequate blood flow to their brain during high-G (gravity) turns and rolls. Without a Valsalva maneuver and special garments, they risk blacking out.

Sorry for the digression.

Unfortunately, increasing the venous blood pressure (by blowing one’s nose) after the soft tissue surrounding the eye has been damaged causes a rapid loss of blood from the leaky veins and profound swelling, which results in a closed eye.

Joe Rogan was absolutely correct – even if he may not know why. (Interesting shirt he was wearing, though.)

Since I answered one for you, please return the favor and tell me what the hell happened to Silva and B.J. Penn at UFC 112.

Anyone? Please!

Dr. Johnny Benjamin is MMAjunkie.com’s medical columnist and consultant and a noted combat-sports specialist. He is also a member of the Association of Boxing Commissions’ MMA Medical Subcommittee. Dr. Benjamin writes an “Ask the Doc” column every two weeks for MMAjunkie.com. To submit a question for a future column, email him at askthedoc [AT] mmajunkie.com, or share your questions and thoughts in the comments section below. You can find Dr. Benjamin online at www.drjohnnybenjamin.com, and you can read his other sports-related articles at blog.drjohnnybenjamin.com.