Its annoying when they die, and theyre carrying loads of stuff.

When Lydia died, I only realized she died about 10 minutes later, and Id completely forgotten where she was as I waited and she never turned up, therefore all the things shes carrying is lost (well I dont know where her body is)

If you lose them, they SHOULD go back to either your house or where you found them. Sometimes it takes a lot of time though. I think they actually walk there or something.

Another thing is that NPCs can't kill your follower. But you can kill your follower. I've killed Lydia with friendly fire. I just left her dead and moved on though.

umm... NPCs did kill my follower once xD... there were too many of them

If they did, it was a bug. They should just kneel down and pop up again later.

i dunno, ive heard people say their follower died in combat, permanently. This is confusing

Your companions die..

They need to be hit with a kill shot ability. Basically works like this.

Your companions health bar runs out she/he will take a knee get up in a few seconds with full health and go back to fighting. But if your companions health is low and she/he gets hit with a special attack animation or powerful attack she/he is straight up dead. If you think im lying let him/her solo some bosses or giants/mammoths she/he will die a lot.

I fought a giant with Lydia and at the end of the battle I couldn't find her anywhere. I figured the giant probably hit her and she flew a mile away. So I fast-traveled somewhere and then she appeared right with me.