A useful League of Legends infographic has been shared that helps players make sense of all the different health bar symbols and statuses following the continued health bar updates.
Starting last year, the health bars in League of Legends started undergoing some changes that would feature status effects more prominently while also changing the way that health is depleted and restored. The changes so far include violent shakes when taking on a burst of damage, icons that clearly show status effects during cluttered teamfights, and exploding health bars for structures like turrets that are blown up.
Riot Ququroon – a QA analyst for Riot Games and the same Rioter who introduced players to other big improvements like the skin portraits being added to teach champion – shared an infographic on Twitter that helps break down all of the many debuffs and other effects that take over players' health bars. It's fairly easy to tell what most of them mean when they have an easy to understand icon with an effect such as the symbol for Asleep, Feared, and Charmed, but other effects aren't quite as easy to decipher. If an ability is being used on you and you know what the enemy champion does, you'll probably be able to tell right away what's happening, but in those busy teamfights, the infographic above should clear up any questions about the effects.
Even with the names and symbols provided for all of the effects, there were one or two that still had players stumped. One of those was Disarmed, a debuff that might not be seen as often. The effect does exactly what the name would suggest and makes it so that players can't attack, as Riot Ququroon explained. However, players will never actually see this in-game since it's a debuff that's reserved solely for Amumu's ultimate, an ability that also roots the enemy. Because of this, the root takes priority and will be the debuff icon shown.
The most recent health bar update came in Patch 8.2 with some slight adjustments and the option to turn off health bar animations in the game's settings.