(CNN) The road to recovery for the dozens of injured survivors of the Orlando shooting is likely be long and painful, if they can ever fully recover.
Physical recovery from a gunshot, even if someone is only grazed, can take from months to years; the psychological consequences can last a lifetime.
"I tell my patients, if you have a major gunshot wound, it will take you at least a year to get back to where you were before," said Dr. Bryan C. Morse, a trauma surgeon at Grady Memorial Hospital in Atlanta and assistant professor of surgery at the Emory University School of Medicine. "And that's if everything goes well and you have a good support system at home, as well.
"There is also a lot of new data coming out on PTSD disorder related to this kind of violence, and that can be lifelong."
Morse's hospital is the largest Level I trauma center in Atlanta. On an average Thursday through Sunday, the hospital will treat about 10 gunshot victims a day. The numbers could be higher during the warmer months that some call "trauma season," though he noted "the trauma season really is all year-round in Atlanta or in any large city."
Though the mass shooting in Orlando was the worst in modern history, such incidents have been escalating in the United States, which has more mass shootings than any other country.
In the United States, someone experiences a gunshot every 4 minutes, 44 seconds, studies show. Approximately 111,000 Americans are shot annually. About 33,800 people die as a result of those injuries, so about 77,200 people are recovering from gunshot wounds each year.
The American Medical Association labels gun violence a public health crisis and there has been a recent call to action from physicians.
American medical personnel have a lot of experience treating gunshot survivors, but there is only so much a doctor, nurse or therapist can do to speed healing.
Many factors come into play in gunshot survival, and the same is true with recovery. Statistics show that a bullet in the head, spinal cord, chest or stomach may be a lot harder to survive or recover from than being shot in an arm or a leg. If the person is shot at point-blank range and the bullet shatters a bone or hits an artery, or if there is a secondary infection, recovery time may be equally extensive.
One of the factors that best predicts recovery time is where the person has been shot. Studies show that patients can survive shots to the head, but the chances of recovery from a shot to the head, heart or torso can be low. Many of those patients will bleed to death long before they get to the hospital. Even if physicians can repair the injuries, those shot in the stomach, for instance, may still die from secondary infections.
The other factor to significantly increase someone's chance of survival is whether they can get to a Level I trauma center quickly. Some have theorized there were a large number of survivors in Orlando because the Pulse nightclub was only blocks away from the city's trauma center. Many of those who were injured could be treated quickly.
Several other factors can affect survival and treatment. Of course, every case is different, but studies show that people who are young, fit and healthy tend to recover faster and may do better with rehabilitation. Women tend to have a better chance of surviving a gunshot wound. People of color do not do as well as others, studies show.
There's even research that suggests that if you get shot on the left side of your heart, you don't do as well as being shot on the right, because you can lose more blood.
Another factor is the kind of gun used and how close the shooter is to the victim. In the case of Orlando, the assault-style rifle used in the attack delivered the bullets with much more force than a handgun would, causing more damage. The weapon could also fire multiple bullets, increasing the chance someone would have to recover from multiple wounds.
In general, trauma doctors are seeing more patients with multiple wounds these days, and that can slow recovery, studies show.
Recovery, again, will depend on where or how someone is shot. A team will immediately assess the damage and will address the worst problems first.
"I had a person with a celiac artery injury who had at least four operations in the past week who also has a shattered leg bone, and we can't even deal with that yet," Morse said.
A patient can spend months at a hospital, during which time they may have several surgeries, including orthopedic, vascular and neurological. They will need further tests like CT scans and possibly surgeries after they get out to reconstruct bone or to repair internal organs. When someone's colon is severed, for instance, they might have to wait a year for the swelling to go down, and only then can they have surgery to reattach it. Some may be permanently disabled.
Then there's the therapy. "This is a major life change that is extremely scary," said Dr. Elliot Roth, the medical director of the Patient Recovery Unit at the Rehabilitation Institute of Chicago. That center tries to help patients get back full physical function and mental health, and it offers programs to reintegrate them to the community.
After a gunshot wound, his team will assess what the patient needs and will work with them on motor, memory and language control if they have suffered head trauma.
They'll work with a patient to build strength in limbs that have been shot. Speech-language pathologists will work with patients who have trouble with language, and the center offers psychological help for those who struggle with emotional issues.
The team will also develop pain management strategies and help patients strengthen their bodies to cope with injury.
The psychological consequences can be especially problematic and can complicate recovery.
"People may experience nightmares, hallucinations. They may get depressed or remain hypervigilant, and even little things may disrupt their sense of well-being, making recovery that much harder," Roth said.
Some also struggle with guilt or anxiety over having survived when others didn't.
Roth has seen anger and sadness. Some of his patients become philosophical. Some respond well to loved ones' attention while others struggle, Roth said.
A rehabilitation team will work to figure out what best motivates a patient to get better, "whether it is encouraging them, cajoling or being stern," Roth said.
Another big factor in a gunshot survivor's recovery is their community. Though a patient's community can be fragile, having even a handful of family members or friends can help.
"A big part of the person's recovery is the support someone gets," Roth said. "To recover, they need support from their loved ones and from having strong family ties or ties to friends or loved ones who can be their advocate."