In The Dark Knight Rises, Bane's ailment is never explained. All we know is that his breathing apparatus keeps him alive (and pain free).
What happened to Bane that requires him to wear such an apparatus? How close is the depiction in the film to that present in the comics?
Bane suffered a vicious attack earlier in his life, as depicted in the film. This then causes him permanent severe pain. From then on, he needs to always wear the mask, as it provides him with relief from the pain:
Nolan has revealed that Hardy's audio-muffling mask is actually pumping Bane's body full of anaesthetic. "Bane is ravaged by pain from a trauma suffered long ago," he explains.
The film Bane is largely similar to early Bane in the comics. In the comics, his mask is basically a Luchador mask. In his early appearances, he had a tube that went from a device on his forearm to the back of his head. This administered a drug called Venom, which was responsible for his superhuman strength, along with providing superhuman regeneration. He later stops taking Venom, as it's highly addictive, and he attributes some of his defeats to its influence. After freeing himself from Venom, he becomes a bit more of an anti-hero instead of a straight villain that he was in his initial appearances. In addition to his strength, the Bane of the comics is a genius, having spent his youth developing his mind in addition to his physique.
His initial appearance was in the Knightfall story arc where he wears down Batman and eventually breaks his back. He accomplishes this by first releasing the inmates of Arkham Asylum. Batman spends 3 months capturing the escapees, exhausting himself in the process. Then Bane ambushes him. Bane had deduced that Bruce Wayne was Batman, and attacked him in Wayne Manor. Due to his superior strength and fighting skills, along with Batman's exhaustion, Bane defeated Batman and broke his back. This is echoed in the film, but doesn't play out exactly the same way.
According to this site, which is in turn citing a tie-in book called The Dark Knight Rises: The Secret Files Scrapbook, this is the reason Bane wears the mask:
...he must wear a breathing apparatus that feeds him with pain relieving gas due to an old injury. He's never been photographed without his mask and only a handful of people have seen his face.
In the Batman comics, Bane wears a full mask that doesn't seem to serve any purpose than to disguise his identity. He's also huge -- much larger overall in every dimension than his movie counterpart. Remember Bane is a user of the Venom drug, though, so it's hard to tell what negative effects it's had on him overall.
My best guess to the purpose of the mask is to make viewers wonder-- if you cannot see Bane's mouth, you want to know why you can't see it. This problem, not knowing, has been known to drive people mad. (Nathaniel Hawthorne published a successful short story about this weird phenomena.)
Bane wears the mask, because as seen in the film (and you can read it online on the Dark Knight Rises database), Bane was left with spinal injuries — hence the big scar up his back; and after successfully surgery, Bane is left in severe pain… so he uses the mask to breath in a pain-relieving chemical to keep his pain at bay.
He doesn't need it in order to breathe and stay alive per se (in the film) but to administer inhaled anesthetics in order to ease the pain left from old injuries suffered at The Pit.
The fact that he has to permanently wear it and quickly gets incapacitated the moment that Batman detaches a few tubes (punching him a couple of times during the final fight) proves that...
A) The pain truly is exorbitantly high.
B) Bane has a very low pain-tolerance curve in the afflicted areas of his body (again the face) which usually happens to scarred tissues and surroundings.
AND / OR
C) Bane has developed a severe case of drug dependency over two decades of slow periodic administration, which means he will need to use larger doses as time goes in order to feel better and the slightest interruption of said dosage will cause the pain to spike and hit him hard.
I'ma bet it's a combination of all three aspects (mainly the last one) as to why the mask is so important to him in the movie.
Bane wasn't lying when he delivers his "it would be extremely painful" line, which serves as a warning to the other guy as well (double meaning).
What I'm truly curious, though, is as to what exactly does he receive that eases his pain without compromising his awareness and consciousness xD (anesthesia wasn't exactly a favorite subject at med. school so I can't really tell which drug(s) is Bane using).
----- OKAY -----
Now that the whole mask thing is out of the way, I can now focus on your question as to what exactly might have happened to the film version of Bane and since there's no official backstory as to the exact kind of trauma he suffered I'ma speculate based on what I know.
First, I'ma tell you what kind of injuries/illnesses he DOES NOT (or is highly unlikely to) HAVE:
"(...) Take a look: his speed, his ferocity, his training. I see the power of belief. I see the League of Shadows resurging" - Alfred
Bane's physicality is mostly consistent throughout the film. His combat prowess shows he's likely to be in peak condition and is initially superior to Batman (yes he had his issues too to I know)
We see him clinging with one arm at the plane scene, climbing down the sewer chain with ease, beat up people with a very few yet powerful hits, perform special moves during his fight against Batman and even carry him high enough before fracturing his lower back's vertebrae.
Curiously enough, it calls the attention that he always does everything rather slowly, one could argue it's because of his "breathing problem" I will disagree:
He has a cool-toned fair skin with no visible color changes such as:
Pallor, which would suggest anemia (low hemoglobin levels with/without low red blood cells (RBC)).
Cyanosis, which would suggest skin hypoxia and hypoxemia (low di-oxygen levels in his tissues and bloodstream respectively).
Blush, which would suggest polycythemia (high amount of RBC).
Jaundice, which would suggest hyperbilirubinemia (which happens either when RBC die en masse or the person suffers from liver injury/failure).
Earthly, Blackened skin and the like, which would suggest an array of different illnesses such as chronic kidney disease, Addison's disease, insulin resistance (like in diabetes) etc...
The first three I mentioned are often expressed by two important symptoms which are dyspnea (a sense of breathing difficulty during exercise which becomes evident whenever we see a person gasping for air) and chest pain which it can go from palpitations (perceivable accelerated heartbeats) to angor pectoris (as seen in patients with heart attacks and heart failure) depending on the cause.
Bane shows none of this, nor any other correlated symptoms and signs of fatigue, respiratory failure, nor congestive heart failure (no wet nor dry coughing, no wheezing, neck/torso muscles stretching, etc).
As for the latter two skin signs. Should he suffer from a liver, kidney, or pancreatic disorder as mentioned before, it's unlikely that he would be capable of maintaining his muscles in shape or possess such raw energy when delivering his attacks.
A failing liver cannot store glucose for later use, a diabetic patient cannot use said glucose properly and begins creating more by destroying the muscle and fatty tissues which causes the person to become emaciated. Furthermore, a failing liver and kidney can no longer process toxic substances from the bloodstream causing the person to suffer from drowsiness and convulsions (none of which are present in Bane).
BTW the whole throat injury is rubbish. There are no visible injuries in any of the pics above, and if he had inner injuries such as the ones seen in people with laryngotracheal burns through inhalation...
...then his mask would also need to be connected to a respiratory tube inserted into his neck (A.K.A a tracheostomy surgery)
Not to mention it would also make it impossible for him to be such a fluent and well-spoken orator ;)
----- ALRIGHT -----
Now regarding Bane's possible injuries:
LET'S FOCUS ON THE FACE, FIRST
As we can see....
It's perfectly normal!
:)
Okay, terrible joke.
If you're the sensible type you might want to close your eyes and scroll down a bit, I'ma try to censor some of the pics.
"- Many years ago, it was a time of plague, some of the other prisoners attacked Bane. The doctor's fumbling attempts to repair the damage left him in perpetual agony. The mask holds the pain at bay" - Pit prisoner
Two things come to mind:
- LEPRAE, AKA Skin tuberculosis. ("THE PLAGUE")
Considering the Pit - a prison and therefore, very overcrowded place - seems to be located in a 3rd world country with little access to clean water and proper sewage there's a vast array of contagious diseases to appear such as the one I mentioned which causes ulcers that slowly eat the skin (and flesh underneath) away.
Are there other bacteria and viruses capable of doing such grievous damage?
OF COUUURSEEHH
However...
That doesn't seem to affect him right now
Should the person suffer severe and open injuries, the mycobacteria will invade the soft tissues with ease and create something similar as to the cartoon shown above.
which leads me to...
MAXILLOFACIAL TRAUMA or FRACTURES (THE ATTACK)
A well-placed, strong human punch has the ability to fracture the bones in the face, and since Bane pretty much gets mauled by a large prisoner gang he most definitely got punched, kicked, and stomped countless times chances are this took place indeed.
I've seen real-life facial fractures, but you don't normally see large portions of the skin/flesh torn open, but rather a massive swollen face with a dark violet/blueish hue from all the blood located beneath:
I've also seen examples when the flesh does get torn asunder, but this usually happens with high impact trauma, be it passive (deadfall, cliff-fall) or active (wall-fall, vehicular accidents, etc). Human power alone is less likely to make it happen, however, it was a gang so there's the possibility still.
Now, whenever trauma takes place, even if we don't quite see a wound in place, it facilitates the access of microorganisms (mostly bacteria) that cause infection.
Add the fracture and you give them an easy access to the bone marrow where they can feast with freshly young RBC and fat. Not to mention an easy access to the bloodstream and cause sepsis later on (which means Bane must be a really resilient s.o.b)
Considering the doctor had to use everything he had at his disposal to save his life and fix his face after the trauma and the place he's at, chances are that Bane suffered an added infection to a severe facial fracture which might have eaten away a part of the skin by the time Ras' shows up...
But then you have Hollywood's lazy representation of his injuries (must be the PG rating thing again)
Still, I will bet my own license that his face's injuries are somewhere in between. Assuming Thalia meeting her father (one wonders how she knew where to find him) and him assaulting the pit took him a few months, you have more than enough time for soft tissue infections to ensue.
It's also important to mention that afflictions such as this have the potential of leaving the local area undergoing chronical inflammation, thus decreasing the resistance of pain due to an often release neurotransmitters, such as one called P-Substance.
Would losing his nose cause Bane severe breathing difficulties? Maybe a bit at first, but as described earlier, his respiratory and circular systems still remain operational.
NOW, LET'S FOCUS ON HIS BODY
The one thing that draws my attention is the large keloid scar on his back, all the way along his spine
The scar goes all the way up to the cervical vertebrae.
Now, I'm not a neurosurgeon, but I'm still going to give it a try...
THE DOCTOR PERFORMED AN EMERGENCY COMPLETE LAMINECTOMY ON BANE IN ORDER TO SAVE HIS LIFE ... THIS can be a big issue:
Bane got punched, kicked, stomped, mangled, etc, everywhere and his back could've also suffered the worst: vertebrae fractures, vertebrae luxation, vertebral disc dislocation, etc.... this can cause one very dangerous thing known as Neurogenic Shock due to spinal cord concussion, crushing, and/or section (the latter two seems far-fetched since Bane can still move).
Long story short, Neurogenic Shock kills you and the surgery mentioned earlier decompresses the afflicted spinal cord, saving your life. Since there are no x-ray, CT scan, nor MRIs available in the pit, the good doctor had to open the entire laminar tissues surrounding the spine, all the way, to locate the exact cause of Bane's Neurogenic Shock and save his life...
Once more, add the local surgery infections, the chronically inflamed tissue, and you got a recipe for a life of perpetual pain, and... long dissability (Bane's I never escaped line).
However...
Through the power of will (Or Belief as Alfred put it) he too rose from his injuries (with the help of the mask) overcoming any or most disabilities.
The mask, since it gives him anesthetics periodically not only nullifies pain but any kind of sensation which is summed with any residual damage at his peripheral nerves (either from the surgery itself or the beating he took) means he cannot feel a thing unless the mask comes off and... it could be a reason why he has to move slowly if he no longer feels the floor he's stepping in
Geez... long post, but I think that's how exactly Bane's issue came to be in TDKR film.
Bane's face is most likely extremely disfigured also. That's what he means when he says the mask contains his pain. Maybe his pain is because he was disfigured and his face is shattered. He knows that anyone who looks at what's left of his face will be disgusted, horrified and shocked. It protects his shattered features and allows him to breathe in a painkiller contained and distributed by the mask while securing facial muscle integrity.
Bane wears a mask for three reasons:
Bane got his injuries after helping Talia al Ghul escape the pit. The other prisoners and doctor beat him up beyond repair...well according to the movie anyways
The breathing mask was only used in the movie. The venom he has pumped into him in other placed is injected into his body, not in gas form the mask is only to hide his face and ID.
Bane wears a mask because when he was helping the girl to escape the prison long ago, others cut his throat. So he found this mask to breath.
So basically bane breathes in venom to stop himself feeling pain
Venom is a pain relieving chemical that gives bane superhuman strength an is responsible for how fast he is
When bane was younger he used to fight a lot of men at the age of 10 to protect a girl he beat the men up but they used to still hurt bane.Bane went to the doctors and they gave him a mask that he breathes in a pain relieving chemical that stops him
That's why in the dark night rises towards the end when batman punches bane round the face you an hear gas coming out and bane starts to get weaker and weaker but he still decides to fight batman. Batman beats him up and then this girl that bane used to protect stabs batman and says a few words and then bane starts crying because it had reminded him of when he was younger
Bane was good guy. Then he turned bad. He had a gas named Venom in his mask to allow him to breathe. He needed the mask because his throat was slit. Also, beneath the mask he doesn’t have a nose.
