The truth of the matter is that with 16 oz gloves, headgear, and an ounce of skill there is little chance you are going to be seriously hurt. Full speed blows to the head are absorbed quite well while blows to the ribs will probably cause bruising. Again, it all depends on who is boxing, but that is the generality of it.
Now for a boxer the best thing to do is learn some defense. This minimizes the number of punches the boxer is going to have to deal with altogether. There are many things a boxer can do to either avoid being hit overall or at least absorb some of the incoming power so they don't do as much damage.
Another thing boxer’s are going to have to deal with is flinching. It is a perfectly natural reaction, but a boxer has to realize that when closing their eyes, you lose contact with your opponent and that is not good. Always keep your eyes on your opponent.
Keep your eyes on your opponent or how can you react to what he is doing? So what are your courses of action when that punch is coming in?
Stance and Footwork
A boxer’s stance is their best defense. If they keep their hands up, elbows tucked into their sides and chin down, everything is protected, body, head and chin. This combined with their constant motion or rhythm will keep them out of trouble most of the time. Never forget the basics.
Slipping slightly rotates the body so that an incoming punch (usually the jab) passes safely next to the head. The boxer sharply rotates the hips and shoulders as the opponent’s punch arrives. This movement turns the boxer’s chin sideways and allows the punch to “slip” past. Once the punch slips by return back to your stance. You can slip to either the left or the right side.
Bob and Weave
Bobbing moves the head laterally and beneath an incoming punch. As the opponent's punch arrives, the boxer bends the legs quickly and simultaneously shifts the body either slightly right or left. Once the punch has been evaded, the boxer "weaves" back to an upright position, emerging on either the outside or inside of the opponent's still-extended arm. To move outside the opponent's extended arm is called "bobbing to the outside". To move inside the opponent's extended arm is called "bobbing to the inside".
Parrying or blocking uses the boxer's hands as defensive tools to deflect incoming attacks. As the opponent's punch arrives, the boxer delivers a sharp, lateral, open-handed blow to the opponent's wrist or forearm, redirecting the punch.
In order for a boxer to duck his opponent’s punch he must bend at the knees and that lowers the torso. Then he will bend forward and that lowers the head allowing him to duck the incoming punch. After ducking the punch immediately return to the guard position.
Covering up is the last opportunity to avoid an incoming strike to an unprotected face or body. Generally speaking, the hands are held high to protect the head and chin and the forearms are tucked against the torso to impede body shots. When protecting the body, the boxer rotates the hips and lets incoming punches "roll" off the guard. To protect the head, the boxer presses both fists against the front of the face with the forearms parallel and facing outwards. This type of guard is weak against attacks from below.
Clinching is a rough form of grappling and occurs when the distance between both fighters has closed and straight punches cannot be employed. In this situation, the boxer attempts to hold or "tie up" the opponent's hands so he is unable to throw hooks or uppercuts. To perform a clinch, the boxer loops both hands around the outside of the opponent's shoulders, scooping back under the forearms to grasp the opponent's arms tightly against his own body. In this position, the opponent's arms are pinned and cannot be used to attack. Clinching is a temporary match state and is quickly dissipated by the referee.