Every Damage Type Ever

I've thought more about the internal damage type, and I'm thinking I may be able to throw Cold under its name, since cold damages your insides, and also possibly electricity, since it harms your nerves.
Another idea I have is that maybe internal damage is the result of other damages. Impact breaks your bones, causing internal damage. Puncture damages organs and blood vessels, causing internal damage. Being Heated over a slow fire probably cooks your insides as well.
If each damage is represented with a die roll, and defense is represented the same way, any damage that gets through would harm you. Perhaps cold and electricity would have the ability to surpass this die roll.
Another option would be to throw these under the Special damage category that I think I may add, which would encompass anything that is unique and hard to counter.

@AdamRobinGames-ARG - I could. Not sure what I would call each, but might be interesting. A character could have an emotionless personality which makes them immune to emotional damage, but not to mental damage.

@Isegrim - Starvation. I'm not sure about this. It's certainly a damage type, but I'm not sure if it's significant enough to merit it being its own category. Maybe Special damage? I'm not sure. Dehydration is a somewhat similar case. It's not exactly heat, though maybe it could cause a stroke. I might but it under Ailment, and maybe do the same with starvation, since both make the body unhealthy and can cause death. It's a bit abstract, but whatever.
A certain balance needs to be made between covering everything and having too many damage types.

@Tim Edwards - Concussions would be a mixture of Trauma damage and Stun. By stun grenade, do you mean a flashbang? Because that would purely be Stun, I think.
You do bring up a valid point with the way in which emotion is different than mental damage. Again, I think it's about striking the balance between too many damage types and not enough to cover everything important.

The main things that determine whether something deserves its own damage type are:
a) Its effect and/or the way in which it damages the human body is unique and cannot be replicated by other damage types.
b) It is common enough to merit its own spot on the list.
c) It is something that causes actual damage to an individual. i.e. it would cause a unit's health to deplete.
d) It is useful in combination with other damage types to be able to recreate certain attacks. i.e. Ailment can be combined with Puncture to create poisoned arrows. For instance:

Impact:
a) It flattens and crushes human bones and limbs. 2/2
b) Maces, clubs, wrecking balls, boulders, and anything travelling fast fall under this category. 2/2
c) It literally breaks bones, so it definitely qualifies. 2/2
d) Impact + Puncture creates bullets. Impact + Heat creates explosions. Very useful as a damage type. 2/2

Heat:
a) It burns off skin and melts stuff. 2/2
b) Fire, explosions, heat waves, lightsabers and energy blasts all fall under this category. 2/2
c) It burns and melts human parts, so it definitely damages. 2/2
d) Heat + Impact creates explosions. Heat + Puncture creates flaming arrows. 2/2
Here are a few that didn't make the cut:

Radiation:
a) Isotopes cause poisoning in the blood (or something), and it can burn human skin. This is the same as Heat and Ailment, so it is not unique. 0/2
b) Nukes. Nuclear meltdowns. Maybe some things in sci-fi, but really not many things fall in this category. Radiation is not a super common thing. 1/2
c) It definitely damages the human body in a real way. 2/2
d) Ehh... Not really. 0/2

Electricity:
a) Damages nerves and burns off hair. It's sort of Heat, and could be explained with Stun. Maybe even Trauma. 1/2
b) Magical spells, broken wires, and perhaps sci-fi weaponry fall under this category. Electricity is pretty common in fantasy for some reason, but not as much sci-fi or historical situations. 1/2
c) It messes up nerves, which is not exactly damage in a hitpoints way. The heat is certainly damage, though. 2/2
d) Not many things this can be combined with. It's kind of its own thing and object. 0/2

Cold:
a) Freezes fluids in the body. Causes hypothermia and frostbite. 2/2
b) Freezing spells, Canada and basically anything extremely cold falls under this category. Weather effects can utilize this, but it is not nearly as common as other existing damage types. 2/2
c) It's not completely a literal "damage", except where frostbite is concerned. In most minor cases cold is not a lasting impact, and can go away once one finds a toasty fire. 1/2
d) Mostly fantasy items, I would say, can utilize combinations with Cold. i.e. ice sword (cold + slash), frostburn spell (cold + heat), and pretty much any combination because fantasy makes no sense. 2/2

This is the grading system I use to determine what merits its own spot. As a final one, I'll grade Trauma as two separate damage types: Emotional and Mental.

Emotional:
a) Nothing can replicate the pain of losing a friend or getting a 99.99% on a test (where did you go wrong?). 2/2
b) In large scale battles and dramatic adventures, emotion is certainly a big thing, although having emotional damage is another level of complexity that may be partially unnecessary. 2/2
c) It's certainly an unconventional damage, but it sort of is. It can certainly be more painful than other damage types. 2/2
d) It doesn't really combine with any other damages. 0/2

Mental:
a) The way in which it damages is kind of similar to emotion. It torments one's brain, damaging one's ability to move or do anything. 1/2
b) It is a bit difficult to define, in whether it's physical damage or psychic damage. However, such things as soundwaves, hard blows to the head, Math diplomas, and things in sci-fi could utilize this. 2/2
c) Again, it's not super defined, but it sort of counts as damage maybe. 1/2
d) Doesn't really combine with any other damages, except maybe Emotional, which is why I would like to combine them into one type. 0/2

So this is what I have done to decide. I will add a rubric to the original post for reference.
Also, thank you to you all for the feedback! It's really been super helpful!

@Fri - From now on, I'll use my grading system to explain my thoughts.

Entrapment:
a)It's not exactly 'damage', as you said. 0/2
b) Nets are pretty common, as are other forms in which one traps themselves. 1/2
c) Entrapment doesn't really damage at all, unfortunately. 0/2
d) Being trapped in a net of sharp things like wires can certainly create combinations. Still though, it's not super versatile. 1/2
Thank you for the suggestion, though. I really appreciate it!

The combat is not going to be overly complicated. In fact, I may just keep it as opposing die rolls, since most of the emphasis will be on damage types. Any weapons with the ability to slash or puncture will have a combo of both as their attack.
i.e. sword is 2d slash, 1d puncture, since you mainly slash but you can also stab.