In a fight is there anyway to tell how much life your companion has? I have been in a number of fights with Lydia but never know if she needs healing or not. Do you just guess if they need health or have I overlooked something?

Isn't Lydia marked as Essential? Just find her crouching on the ground.

No, she can be killed. Generally, enemies drop aggro and focus on you when she goes down, but if she was poisoned or lit on fire or if you're not around to catch aggro, she can still die.

I wish her health bar stayed at the top longer but I use Healing Hands on her anyway. It also raises my Restoration. If you're on PC, you can hit the tilde(~) on your keyboard, type getav health (return) and see what her health level is. The highest she has is 158. Then tilde again will close everything up again. Mostly she'll die early on if you hit her with friendly fire but later the strongest enemies can kill her.

:tes:

well lydia just sits in the corner reading or eating all day, everyday so I guess you can tell she has no life

So there is no real useful way to tell how much life they have?

Just from observation, I noticed that she regenerates HP almost instantly (there is a slider bar that will briefly appear)... but if she takes enough damage at once, she can be killed.

From what I can tell, bad guys will temporarily ignore her if she gets on her knees (who could ignore that, am I right?) from heavy damage, but in just a few seconds she's back at full health.

If you look at your follower, the red sliding health bar thing will appear just like it does over enemies etc. but this only works in combat.

If she isn't at full health, she should have a health bar (I've seen it sometimes, anyhow, although I can't say for sure it always appears). As soon at you go "out of combat" (that is, all nearby agro'd enemies dead), she insta-heals, so it can be hard to see this sometimes. You defeat the enemy, go over to heal her up, and she's already fully healed. Se will also heal up during combat, but it seems to take longer, like 30 seconds or so. Or, you can heal her with healing hands if you see her crouching, as the others have said.