The Hemophiliac (badge is for "Losing 10000 points of health"
Losing HP is the easy part, recovering less so. You will likely accumulate a decent amount of lost HP as you play but you can somewhat speed this up with the heal Rig. Fully upgrade your heal Rig and relevant prescriptions (one that regens partially lost health), then load into the "Kill the snitch trial" and take as much damage as you can before resetting and repeating the process.
Also two handy things to note:
1. The in-game badge menu tracks your progress.
2. Leaving a trial after gaining progress still counts towards it.