Sometimes I screw up and lose health to an environmental hazard, but it seems like then the next time I get into a fight, I’ve still got missing health. This is something of a disadvantage.
I get my health restored when I finish a combat sequence, but is that the only way to get health back? Is there any way to restore lost health before entering combat?
You can restore it with anything that gives you experience, including things such as collecting Riddler trophies or completing side quests. You can also heal by dieing or reloading your game, but those will put you back to your last save point, and you’ll lose anything you did afterwards. Personally, I find the easiest way to be just silently taking out a lone guard.