Followers level with you, e.g. if you are at level 16 they will be as well, but their stats do not change. I checked getav health and it returned the same value on a save from level 10 as a save from level 16, getav twohanded likewise showed no increase. Their stats seem frozen from the moment you you meet them. You can work around this on PC by dismissing the follower, then while they are walking away, open up the console, select them, type disable (they will disappear), then type enable. This will force a recalculation of their stats based on current level. You can then recruit them back (if you don't dismiss them at all, none of this will work).

It looks like the designers meant your followers to level with you, as they do increase in level with you, however that is literally the only thing they do. Their stats are not recalculated correctly. This is probably a bug.

edit: Argh, I think this is probably a false alarm. Disregard.

getav and getav seem to operate on the base object which is apparently created for followers (maybe NPCs in general?) when you first encounter them. However getavinfo will return both the base values and the values for that reference, and the reference values seem to be correct. getav works a bit differently than in Oblivion, and getavinfo is a new command for Skyrim. [but the reference value doesn't seem to do anything, see below]

edit2: Myself and a few others have tested this a bit more, and actually it does appear something is going on here. getavinfo does work as explained above, and the 'reference health' is what you would expect, however the damage a follower can take before dying is clearly the *base health*, not the correct value in reference health as returned by getavinfo. So either the intent is that followers do not level up with you, which makes me wonder what reference health is supposed to represent in the first place, or they are supposed to but do not because of this apparent bug.

Bump! Discussion going on at reddit as well:

http://www.reddit.com/r/skyrim/comments/mkg5v/important_console_command_for_pc_users/

Do you notice any difference in his or her strengths in-game? Maybe your follower isn't "compatible" with the specific command, it could be of a whole other 'class' than those who can return a valid health. I'd say, get yourself a follower on level 4, then hack your way to a way higher level and see if in combat they are the same or not?

I wondered if this was the case because Lydia is pretty much just company for me now, any real combat with higher level enemies and she loses and crouches down for help very quickly, she can still take normal Bandits, but any enemy higher than a level 10 and she stuggles, I am level 30 now and was given Lydia at about level 4

Someone tested this out by attacking their follower and noting how many hits it took to kill them. Then they disbled and re-enabled the follower to get new stats. The follower took many more hits before dying. (Health increased.)

My question is, do we all agree this is a bug and they SHOULD be getting new stats? I dont want to feel like I am cheating or anything on my first playthrough. What if I never read this message board post? Would I even notice my followers not leveling with me in-game?? Is it that bad at later levels? They just die in one hit?

I concur, this is happening and is a bug that needs to be fixed. The followers level with you but their stats, skills, health etc. do not ever update. I started using Lydia early on and now that I'm around lvl 26-27 she's constantly getting killed, disarmed and knocked out of fights almost instantly, regardless of the fact that I have her outfitted with high-end gear.

Try getting them to "leave your service", resting for 3 game days in an interior cell like your home but not the same place your companion is, and then rehiring them. I dont have any idea if this would fix the issue or not lol, just a guess based on previous games.

I did the whole disable / enable thing and it updated her stats. I dont know what else this does though, so I'm a bit on edge about it. I just dont feel right going into the console messing with stats and things. Who knows what else that could mess with.

Anyways, I was in my Breezehome and these were my steps:

1. Tell her to go home. (Leave your service.)
2. ~ to bring up console, click on her
3. type 'disable' (she will disappear into the nether)
4. type 'enable' (she will materialize in front of you with all new updated stats)

Bump so more people see.

So, since Uthgerd has demonstrated that she levels Block and Marksman correctly, can we confirm that the intention was for followers' stats to definitely level up with you? I mean, Uthgerd answers that question plain as day I think, eh?

No other "reasonable" explanation exists that I know of. What would be the point of dragging a thin-skinned, low-health, bad-shot, novice-level companion dungeon crawling for ? Just to see them die like wet tissue paper on the 1st hit? Going to go with Bug.

I hope they do level with you. Anything else would be a design flaw in my opinion. Why shouldn't companions level up if the hole world ist scaled...I hope they will fix this with the next patch already, because it would be a serious immersion-breaker, if you had to switch companions every three levels or so.

I tried the enable and disable thing but while it probably did update her stats I noticed that it seemed to cause bugs, namely she kept floating or disappearing half way into the ground. This never happened in my game before the enable disable console workaround so be aware it could cause different problems

A recent post about a flying Meeko revealed yet more issues the game can have, in that case incorrectly calculating mesh offsets. He was able to fix it by going for a swim long enough for the dog to follow into the water decently, so when Meeko came back out the water it recalc ground collision and he wasn't flying anymore.

See if that resolves this too when you get a shot.

Edited:
Note in the case of the dog, he hadn't done anything at all. It simply occured. The dog refused to enter water once, ran off for a shore circle, came back flying. So it can happen regardless, if it turns out related.

Wow, I tested this out this morning. I took my plain Lydia to a fort and let her have fun. She was cut down in seconds. Hardly scratched the bandits. I reloaded, disable/enabled her and then went back to the same fort: she was a beast! Almost tanked the whole room. More effective at blocking, was taking beating, hit harder, etc etc. It was a huge improvement over the previous test.

I just tested this because Lydia was a failure in combat. I stripped her full set of orcish armor(hand me down) and checked her health with getav, 158 health, and I'm level 35. Told her we should part ways. In Breezehome I disabled/enabled her, 490ish health and 164 stamina, her stamina was below 100 before disable. Definitely a bug, but now I'm jealous. She has more health and stamina than I do. I have 400ish health and 140 stamina. We both have 100 magicka so at least the game is leveling her as a warrior style class. Well not "leveling" since it's bugged but the stats after disable. Oh well...

I tried to edit my post but apparently I don't have permission to....odd.

But I just noticed that enchanted gear that has health on it doesn't work on Lydia. Maybe it's intended that way like companions in Fallout NV couldn't use weapon mods. No idea...

This is not a bug caused by diable/enable specifically but, as another user pointed out, a mesh interaction glitch that can happen when actors are spawned for any reason (including a follower simply entering a cell with you upon cell transition when they were far away before.) Disable/enable can, just as entering an interior cell or fast travelling, cause this somewhat infrequent glitch to express itself. The chance is small, but if it does happen then just go for a swim as suggested.

Disable/enable is far safer to use on objects and actors than it was in previous titles because it does not break scripts associated with the disabled reference. You can also use it to clear dragon corpses - and avoid the bugs and NPC behavior issues associated with them.

Thanks for this- worked perfectly.
The Falmer Cave I am currently in at lvl 22 suddenly became a whole lot more survivable without Lydia being one-hit at the beginning of every battle.

Amusingly with this glitch, a well equipped but improperly leveled follower would actually be more useful in many cases if they died. I discovered, after accidentally killing a glitched Lydia in a fight against a swarm of Falmer, that Zombie Thrall Lydia was extremely deadly as a permanent undead thrall.

Well, this explains a lot! I stopped using followers because they would just always die on me in seconds. Thanks for the info!

Just played about 1.5 hrs with the "new" Lydia. its night and day her effectiveness. I'm hoping this is one of Bethesdas higher priority bugs.

They get locked at the level you are when they join you. Or so says the UESP.