On June 1, 2007, during a reconnaissance operation in Iraq, Army Sgt. 1st Class Brian Field's life changed forever.

During that operation the native Napan stepped on an improvised explosive device. The IED blast resulted in such grave injuries that doctors had to amputate Field's legs five inches below his knee. Since the beginning of the month, Field, 33, has had 12 surgeries, and is expected to have at least 10 more.

Field's aunt, Karen Ames of Napa, has since embarked on a mission to help wounded soldiers get the support and recognition that she said they deserve.

"Not much is known about those who are wounded," Ames said. "You may hear that one man was killed, but how many were injured? And it happens every single day."

Field grew up in Napa until age 11, and attended St. John's Lutheran School. Unfortunately, he now joins more than 800 of soldiers that have lost an arm, a leg, fingers or toes.

More than 100 are blind. Dozens need tubes and machines to keep them alive. Hundreds are disfigured by burns, and thousands have brain injuries and mangled minds.

These are America's war wounded, a toll that has received less attention than the 3,500 troops killed in Iraq. Depending on how you count them, they number between 35,000 and 53,000.

More of them are coming home, with injuries of a scope and magnitude the government did not predict and is now struggling to treat.

"If we left Iraq tomorrow, we would have the legacy of all these people for many years to come," said Dr. Jeffrey Drazen, editor-in-chief of the New England Journal of Medicine and an adviser to the U.S. Department of Veterans Affairs. "The military simply wasn't prepared for its own success" at keeping severely wounded soldiers alive, he said.

Survival rates today are even higher than the record levels set early in the war, thanks to body armor and better care. For every American soldier or Marine killed in Iraq, 15 others have survived illness or injury there.

Unlike previous wars, few of them have been shot. The signature weapon of this war -- the IED -- has left a signature wound: traumatic brain injury.

Soldiers hit in the head or knocked out by blasts -- "getting your bell rung" is the military euphemism -- sometimes have no visible wounds but a fog of war in their minds. They can be addled, irritable, depressed and unaware they are impaired.

Only an estimated 2,000 cases of brain injury have been treated, but doctors think many less obvious cases have gone undetected. One small study found that more than half of one group of wounded troops arriving at Walter Reed Army Medical Center had brain injuries. Around the nation, a new effort is under way to check every returning man and woman for this possibility.

Some of those on active duty may have subtle brain damage that was missed when they were treated for more visible wounds. Half of those wounded in action returned to duty within 72 hours -- before some brain injuries may have been apparent. The military just adopted new procedures to spot these cases, too.

Back home, concerns grow about care. The Walter Reed hospital scandal and problems with some VA nursing homes have led to calls for better care for this new crop of veterans.

A lucky few get Cadillac care at one of the VA's four polytrauma centers, where the most complex wounds are treated with state-of-the-art techniques and whiz-bang devices like "power knee" or "smart ankle" prosthetics. Others battle bureaucracy to see doctors or get basic benefits in less ideal settings.

Mental health problems loom large. More than a third of troops received psychological counseling shortly after returning from Iraq, and a third of those were diagnosed with a problem, a recent Pentagon study found. The government plans to add 200 psychologists and social workers to help treat post-traumatic stress disorder and other issues.

No one knows what the ultimate cost will be. Harvard University economist Linda Bilmes estimates the lifetime health-care tab for these troops will be $250 billion to $650 billion -- a wide range but a huge sum no matter how you slice it.

Cost of war

Counting the wounded can be contentious. Earlier this year, the Department of Defense changed how it tallies war-related injuries and illness, dropping those not needing air transport to a military hospital from the bottom-line total.

Bilmes, the economist, thinks this is disingenuous.

"An accident that happens while they're there is a cost of war, particularly when you factor in the length of deployment" and injury-inducing conditions like very hot weather, carrying heavy packs, and more vehicle accidents because it is not safe to walk anywhere, she said.

As of June 2, 25,830 troops had been wounded in action. Of these, 7,675 needed airlifts to military hospitals and the rest were treated and remained in Iraq.

There were another 27,103 non-battle-related air transports. Of those, 7,188 had injuries. Most occurred from vehicle accidents, training or work-related accidents. Ten percent were sports injuries, said Dr. Michael Kilpatrick, who tracks this information for the Defense Department.

Nearly 20,000 of these "non-hostile" airlifts were for illnesses or medical issues: general symptoms like fever or pain needing tests or evaluation; back problems; psychological problems adjusting to being in a war zone; "effective psychoses" (not able to function or care for themselves); neuroses; respiratory or chest symptoms; depression; head and neck problems (including traumatic brain injury); epilepsy; infections, and muscle pulls and strains.

"I don't want to try to say these are not war-related. Being in the military is a very physically demanding job," Kilpatrick said.

For stress-related problems, the military tries "three hots and a cot" -- warm meals and a chance to sleep. Most of the time it works and troops return to their unit, Kilpatrick said.

Of the troops air evacuated to the military hospital in Landstuhl, Germany, 20 percent return to Iraq and 80 percent go back to the United States for more care or disability discharge.

Of the half-million troops who have left active duty and are eligible for VA health care, about one-third have sought it. The most complicated cases end up at one of the four polytrauma centers, in Tampa, Fla.; Richmond, Va.; Palo Alto; and Minneapolis.

These were formed after doctors realized they were missing problems -- amputees who were confused and unable to put on their prosthetics because of undiagnosed brain injuries, and guys who could remember their therapy dog's name but not their doctor's, or who could carry on a conversation but not recall what they had for breakfast.

Troops at these hospitals have an average of six major impairments and 10 specialists treating them.

"The important thing to realize is you could have all of them at once" -- trouble speaking, seeing, walking, hearing, etc., Scott said.

Most of these injuries are caused by IED blasts, which send a pressurized air wave through delicate tissues like the brain, sometimes send it smacking against the inside of the skull and shearing fragile nerve connections that control speech, vision, reasoning, memory and other functions. Lungs, eardrums, spinal cords -- virtually anything -- can be damaged by the pressure wave. Injuries also come from collapsing buildings, flying debris, heat, burns or inhaled gases and vapors.

"Many of these you can't see on an X-ray," such as glass shards that can cause internal bleeding, Scott said.

In prior wars, one of every five to seven troops surviving a war-related wound had a traumatic brain injury, the military estimates. It's much higher in this war.

A pilot project at Walter Reed in 2003 to screen 155 patients returning from Iraq found that 62 percent had a brain injury.

"This is a very rapidly evolving area as a disease," with no screening test, agreed-upon set of symptoms for diagnosis, or even a billing code, said Kilpatrick, the military doctor.

Much needs to be learned about how to treat these injuries, he said, but credited the military medical staff for having the chance.

"It's just amazing to me every day when I look at these numbers," he said. "The good news is that the majority of these people who become ill or injured ... are going to survive and are going to be able to return either to the military or to civilian life and be productive."

Register Staff Writer Cristina De León-Menjivar contributed to this report.