It takes a special kind of person to join any branch of the military. The psychological and emotional strength has to be top of the charts excellent. Physical conditioning comes with the infantry and advanced infantry training. Special training in pain management is quite intense. Could you do it? If you make it past the rest, you have to show you can manage pain on top of it, because your platoon and your band of fellow soldiers depend on you to keep moving regardless of how much your wounds hurt in the midst of a battle. Here is what you would have to show.
Bodily Stress, Minor Injuries, and Fatigue
As a soldier, you have to completely and utterly ignore that the body aches from stress, the minor injuries from cuts, scrapes, and near misses with bullets, and fatigue from lack of sleep. You learn this first in infantry training by the numerous brutal hikes during the day and at night. There are obstacle courses that are nearly impossible for anyone to do, and which almost always result in some sort of injury, but you have to get through them. You will never be injured by bullets in training, of course, but gaining resiliency through the rest of your training you can tolerate such things in the heat of battle.
Major wounds are always at the back of your mind when you are deployed. There are no medications to kill pain when you are fighting. You will be most fortunate if your group even has a medic on hand with clean bandages.
While it is extremely hard to pretend that a bullet in your body or a missing appendage does not hurt, you can learn breathing techniques similar to Lamaze that will help you tolerate the pain until you can get somewhere safe and relatively quiet. Learn these techniques before deployment, and practice them as often as you can. You will find that they help keep you calm and focused, even when you are not in the midst of a shootout.
Despite Your Wounds, Your Body Will Always Fight
It is absolute instinct to survive. No matter how much you want to let go, pass out, and die on the battlefield, your body will push through it and keep fighting to live. Most of the time, the urge to keep going comes from the adrenaline your body is pumping around, mixed with the endorphins the body produces during moments of intense pain. As the endorphins begin to work in conjunction with breathing techniques, the adrenaline will keep you going until you can see a medic. Now, asking once again, do you think you could manage pain like a soldier?