Nanos are microscopic machines that work inside the body. The original nanites worked with the dice codes only to produce the various effects of leveling up, but more recently they have been injecting all Master Dice with ones that do accelerated healing as well to prevent suicide before earning profits.
Nanites are highly specialized for the first body they're put into, and associate themselves to that DNA only. They won't infect others. (AD Day 17, strip 39)
It's best to leave wounds uncovered while the nanites work, as they'll just tear away the wrap anyway. (AD Day 9, strip 22) They are machines and work like machines, following their programming to always work on the worst injury. They will take their materials from wherever they find them,.. fat,.. bones,.. muscle,... they can't tell that they are causing damage in the process. The drinking of Nutramixes help provide the material needed for healing severe injuries without them literally tearing the body apart. (AD Day 9, strip 23) They fix everything, but don't dull the pain. (AD Day 9, strip 24)
Painkillers won't work, and as a matter of fact, they do BAD things, like anesthetics and tranquilizers. Anything that's supposed to dull the pain or knock them out *Other than that powder that Stealth suggested, (AD Day 9, strip 23) since it's made up of a certain chemical designed to tell the nanites to let Lexx sleep.*
Painkillers cause the nanites to become confused as to what they're supposed to be fixing, anesthetics shut them down completely, which then is a bad thing for since they won't heal normally,.. and tranquilizers,... since most are designed to be immediate cause the nanites to become even more confused and wreck havoc on the body. (Basically, they're allergic to these things, even an aspirin will cause more pain than good.)
Fortunately, it is against game rules for anyone to purposely use such things in battle.
The nanos keep a perfect genetic balance. Everything inside works as if they were perfect. If they survive, despite the punishment they may take physically, they will keep them in top physical condition. The nanos don't seem to care much about fixing things on the outside though, which is why they carry scars. They are hasty. The skin is only an enclosure and barrier, that is how they treat it. They will never be naturally sick, they'll never develop certain diseases. They can't contract AIDS, can't get Cancer, can't get anything involving white blood cells as a source of a problem. They will still grow old and eventually their bodies will wear out, ... but their minds would probably wear out before that. If they ever truly 'give up' then the body would go as well.
Likewise things like sunburn are left untreated. They register it as damage, but not anything serious enough to take action - after all, it's only skin. (AD Day 16, strip 27)
- While they normally heal burns, and will treat a bad sunburn eventually, they have a hard time identifying sunburns as damage due to the lack of a fight. (AD Day 17, strip 8)
The nanites take the place of the white blood cells and 'do' away with the immune system because they see it as unnecessary when they fulfill that function. If the nanites were removed, they would have zero immunity and would essentially be a hemophiliac without an immune system at all. They replaced all of it.
They are programmable by sound, as originally created. Most of it has been disabled, but some fail-safes were never found. Very few know the correct sequence of tones, but those that do can shut off the nanites for a time. (AD Day 10, strip 29)
There are also medical nanites that are used to treat injuries. They are applied to a wound to repair it. Six hours later they deactivate and are expelled from the body. (AD day 20, strip 170)
The nanites were designed by another race that does not frequent our galaxy. The core technology was stolen by the ADC and abused. We were gifted a less broad nanite technology for use in healing, which is how the ADC learned it existed. The race that gave us this gift did not approve and no longer have contact with any of us. (AD Day 25, strip 19)
- They were meant for temporary use and were altered for permanent use. (AD Day 27, strip 37)