Can People Heal in Your Setting?

 

Is there a limit to how much damage your character can heal?
>Can they heal injuries the entire way, or just a percentage?
>Does the healing cover diseases and other maladies as well?
>Can they build tolerance against certain types of injuries?

Do their bodies age?
>Until when?

Can fire kill them?
>Can they be incinerated?

Do they scar when they heal?

How fast can they heal?

Can they heal when malnourished?

Can they die (from natural causes)?

Can they be killed?

How does their hair work?

Can they get piercings or tattoos?

Can they pass on any of their healing abilities through sharing their blood?