For anyone who underscores the significance of blood in MMA, ask UFC lightweight Kenny Florian about his 2006 decision loss to Sean Sherk. Behind on the scorecards going into the fifth round, Florian tried to submit his opponent.

"I cut Sean with an elbow," Florian said. He was bleeding all over me. Mentally, someone else's blood pouring in your face and mouth is awful. I took three showers. I can still smell and taste it."

In their first encounter, Sean Sherk's cut threw Kenny Florian off his game. Sherdog.com

When it comes to blood, when is too much too much? What criteria are used to determine a stoppage by the referee or doctor, and how are cuts prevented and handled during a fight?

A cut's location is the most decisive factor.

"When a cut involves the soft tissue of the eyelid, I halt the action and bring the fighter to the doctor," referee John McCarthy said. "These are hard to repair and can do permanent damage."

Cuts inside the orbit of the eye can affect the muscles or nerves (resulting in a droopy eyelid), limit movement of the eyeball (which produces double vision) or affect the tear duct.

Cuts near the lashes, like that sustained by Randy Couture in his 2004 fight against Vitor Belfort, do not appear serious, but can quickly result in blindness without immediate surgery.

Lip lacerations across the vermillion border (the colored portion) result in scarring and difficulty closing the mouth, while cuts inside the ear could indicate a serious skull fracture.

All "pumpers" (arterial bleeding) end fights because they are difficult to control and precipitate significant blood loss.

Scalp wounds, like the one Joe Stevenson suffered against B.J. Penn at UFC 81, can be bloody, but are rarely dangerous unless they obscure a fighter's vision.

Excessive bleeding inside the mouth can make a fighter choke or vomit.

"During the Genki Sudo-Duane Ludwig fight, Ludwig was bleeding so much inside his mouth he was gurgling blood that sprayed into Sudo's face," McCarthy said. "I had to break the action to have him looked at and restarted it from a standing position."

Genki Sudo, bottom, not only had to deal with Duane Ludwig's strikes, but also his opponent's blood. Sherdog.com

Soon after that fight, the rules changed so that if the action breaks for medical assessment, the fighters are put back in the same position to prevent one athlete from gaining an unfair advantage.

There are several situations in which a fight is stopped due to a cut. The first is if the injured fighter is at an unfair disadvantage should the fight continue. Another is if the cut can lead to irreparable damage, should the fight continue. The last is if the fighter is already losing and taking too much punishment.

Unless a cut is too dangerous at the onset, the cutman is given a round or two to control the bleeding.

The keys to stopping the flow of blood begin weeks before a bout.

Headgear is used in the gym to guard against cuts and facial swelling. Florian pre-treats his eyebrows and eye area with Mederma and uses vitamin E on old scars. He avoids using Aspirin and Motrin, which increase bleeding time, and any form of medicinal steroids that thin the skin.

A good cutman can make the difference between winning and losing.

Las Vegas' Jacob "Stitch" Duran began as a cutman in 1985 and has worked on some of the biggest names in boxing, such as heavyweight champion Wladimir Klitschko. Now he is a fixture at UFC fights.

"In boxing, you can do preventative maintenance," said Duran. "In MMA, cuts are almost guaranteed; multiple cuts and head wounds on the same fighter are common. I have established a good foundation that works in MMA. I'll clean out the cut between rounds and look at how bad it is, where the main vessel is, then apply epinephrine [a coagulant]. I'll also ice the fighter every round to contain any swelling."

Duran also uses other coagulants, including avetine and thrombin, but cold, pressure and time will stop most bleeding.

Many fighters can't handle seeing their own blood. "The first time I was cut, it freaked me out, especially having blood in your eyes," Florian said. "Now I have learned to stay calm and deal with it."

In the Dec. 13, 2006, fight between Drew Fickett and Karo Parisyan, Duran took control to reassure his fighter, Parisyan, that he had the fight under control. "Karo got a serious cut on his cheekbone, Duran said. "He saw his face on the big TV screen. By the time he gets to his corner, he can't see and is going crazy. I took it upon myself to tell him, 'Don't worry about the cut. My job is to work on you.' I worked the cut and he won the fight."

Duran knows he is there to try to give the fighter one more round, but that can't always be the case. "There have been times where a cut was too much to handle and I have made a recommendation to the ring physician that a fight stops," he said.

McCarthy also does his part to prepare the combatants before the fight. "I put it to the fighter in the locker room that if they are hurt to a point and they don't want to quit, if they are significantly cut, I will stop the fight," he said.

If a fighter's bleeding is causing his opponent an inability to see, McCarthy will stop the action, bring the injured fighter to the doctor and allow the opponent to have the blood cleared from his vision."I have had blood in my eyes," McCarthy said. "It isn't like water, it is like a thick goop, and it is hard to clear by just blinking."

No one dies from a cut during a fight, but blood frequently influences an outcome. Ending a fight on a cut is typically due to multiple factors that have played out during the preceding rounds. While blood-lusty fans may cry foul, the referee, doctor and cutman are there to enable a fight to proceed to its natural conclusion and allow the athletes to return to compete another day.

Dr. Margaret Goodman, a former Nevada State Athletic Commission Medical Advisory Board chairman and chief ringside physician, contributes regularly to The Ring magazine.