He sometimes uses a wheelchair or cane. He suffers seizures. He's confused and disoriented. He's in and out of the emergency room almost every week.
After three combat tours in Iraq, he suffers from post-traumatic stress disorder and a traumatic brain injury caused by a 2005 roadside bomb.
Litz was among the thousands of Americans who enlisted in the military during a burst of patriotism after the Sept. 11, 2001, terrorist attacks.
Now, a decade later, he has become a victim of the wars spawned by 9/11.
"I feel like I'm broken," said the 30-year-old former Marine sergeant, now a Dallas police officer who can't work because of his health problems.
After intense criticism over its handling of blast concussions, the military has in recent years toughened protocols for handling them. But for Litz and others, it is too little, too late.
Litz relies on the strained medical services of the Department of Veterans Affairs, where psychological injuries and brain injuries compete with the "more real" problems of amputations and other physical ailments.
Litz and his wife call it the "VA machine." Trips from their home in McKinney to the emergency room at the Dallas VA Medical Center are routine.
"The ER will kind of laugh at us, `Are you really here for a migraine?"' his wife said. "They will shoot him up with narcotics and send him home."
Dr. Stephen Holt, the Dallas VA's deputy chief of staff, said VA officials are doing everything they can to help Litz. But he said migraines are typically not considered a medical emergency and are handled by primary care physicians rather than neurologists until more traditional options have been exhausted.
"The bottom line, unfortunately, is that unless we could return Mr. Litz to his full pre-deployment functionality, Mrs. Litz is not going to be happy, and indeed I don't think she should be," Holt said.
Traumatic brain injury and PTSD are the two most prominent injuries of the wars in Afghanistan and Iraq. Nearly one in five returning combat veterans is estimated to have experienced one or both.
These often invisible wounds have left countless veterans besides Litz suffering long-term impairments and struggling with day-to-day life.
"The scariest part is that we don't know the scope of the problem," said Maggie Haynes LaRocca, director of the combat stress program for the Wounded Warrior Project, a non-profit advocacy group for veterans of Iraq and Afghanistan.
"Our families are extremely stressed. . It's just not fair. You send someone away, and you get a completely different person back."
As with so many others, the 9/11 terrorist attacks galvanized Andrew Litz into action. He quit his Regular Joe auto mechanic job in Plano and joined the Marines.
"I felt I should be doing something, anything other than working on cars," Litz said.
He was soon off to the deserts of Iraq, serving combat infantry tours in 2003 and 2004. After the second tour, depression and recurring nightmares set in. He struggled to sleep. He drank heavily.
Military doctors diagnosed him with PTSD. He said he was given depression medication and sleeping pills but no counseling.
Within months of his December 2004 marriage, he was back in Iraq for the bloodiest of his three tours. His unit endured ambushes with rockets, roadside bombs and machine gunfire from an often-unseen enemy.
On April 20, 2005, a roadside bomb rocked Litz's Humvee. It killed two close friends.
"The lieutenant was yelling in my face about what we were going to do, but I didn't comprehend what the heck he was saying," Litz said.
After fleeing to safety, Litz started throwing up and crying and passed out. He said the ensuing days passed in a blur as he repeatedly lost consciousness. He was later diagnosed as having suffered a mild traumatic brain injury.
The symptoms typically go away in a few days or weeks. But in some case, long-term impairment can result, experts say.
On the same day commanders ordered Litz back into the field, he went outside to smoke a cigarette and passed out.
Superior officers still chose to send him back to his squad.
Litz said his migraines and dizziness continued, and he felt unfocused and confused.
Fidel Alcoces, a retired Marine sergeant who was in the convoy, said Litz was a changed man after the explosion.
"He was kind of like a shadow of himself," he said.
David Hovda, director of UCLA's Brain Injury Research Center, said that at the time of Litz's injury, the military didn't have adequate procedures for dealing with blast concussions and didn't realize the serious lasting ramifications of not properly treating such injuries.
"They had no idea what to do," said Hovda, the recipient of a prestigious award this year from the Army for his research into battlefield brain injuries.
If Litz was still suffering symptoms from a concussion, Hovda said, "he shouldn't have been allowed back in the field" because of the danger of additional brain trauma.
Within months of the blast, Litz returned home to a pregnant wife who was then fighting a battle with cancer.
"He slept day in and day out," said Heather Litz. "He was crazy moody. He was very on edge."
Litz sought help from military doctors. His family says they gave him depression medication and sleeping pills and sent him on his way. The Marines honorably discharged him in May 2006.
He worked for a few months as a night stocker at Walmart.
"It was a big change, a really big change from being in the Marine Corps," he wrote in a letter about his life for the VA and charitable organizations. "I felt ashamed. . I was highly stressed and depressed at the time."
Litz still wanted to serve the public. He was hired by the Dallas Police Department.
At the academy, he said, he noticed that migraines came more often and he felt stressed and depressed. Sometimes he felt an uncontrollable anger, and he found himself lashing out at his wife and children.
"He was trying hard to hide his symptoms," his wife said. "He's a Marine, and he was built and trained to fight and never complain."
Litz began missing so much work that someone placed a name tag on his mailbox that read, "Sick Day."
The migraines have recently worsened in intensity and frequency. He is on more than a dozen medications. Certain smells and sounds trigger his PTSD symptoms, including anger and nightmares.
"I could tell he was suffering out in the field," said Litz's commander, Lt. Mike Magiera. "He looked terrible."
Litz stopped being able to go to work July 12. He quickly depleted his paid leave. His family went without a paycheck for several weeks, until officers were allowed to donate their work time so that he could receive a paycheck.
Now he spends his days at home or at doctor appointments.
He is forgetful and moody.
"My own children say things like, `Why doesn't Daddy like us?' or, `Is Daddy ever going to play with me?' and even that `Daddy is brain damaged,"' he wrote.
It took several years to get in to see a VA neurologist. One recently prescribed Botox treatments to try to stop the muscle spasms that may be triggering the debilitating migraines.
There are still worries about paying the mortgage and bills.
A wealthy anonymous benefactor is footing the bill for Litz to see private neurological specialists. An MRI recently found that Litz suffers from seven large bulging discs, including two in his neck, his wife said.
"Because of a certain benefactor we have been able to get answers that the VA should have given us years ago," Heather Litz said. "We know it's going to be a long road yet, but we're hoping to get our life back someday."