Health is one of the five main stats all survivors posess, along with Fear, Fatigue, Hunger and Thirst. The default Health level is 100% for all survivors, with this percentage decreasing every time a survivor is injured.
Injuries can be inflicted either by zombies (By taking the survivor to a zone with a Z-Density above zero) when traveling or scavenging, or by hostile squads. The quantity of lost health per injury appears to be random, with between 15%-30% lost per injury. If a survivor's health reaches zero, he/she will be killed permanently.
A survivor's risk of being injured increases at higher Z-Densities. It also increases when their Fear and Fatigue levels are high and when they are hungry or thirsty. Equipping an Armor, however, can decrease the chances of being injured.
A survivor that has lost health needs to rest in a safehouse to regain it. The time needed to recover can be shortened with the Infirmary and Field Hospital safehouse upgrades.
Health can be partially recovered immediately by using Morphine which can be purchased with NECRA Credits.
A character's health will not regenerate if the squad is moving or traveling to a different area. You must be in a NECRA Safehouse or a User Safehouse.