Healing is a ability to restore an individual to full health or an object to pristine condition. The trigger for this power is love and conversely the trigger for the touch of death, its counterpart power is hate.
This power is mainly possessed by Whitelighters, a warm golden light shines from their hands as they heal injuries and wounds on others. It also mends their charges' torn clothes. This ability has also been shown to heal objects as well, such as when Leo used them on some plumbing pipes and the sign for P3.
There are exceptions however; the inability to heal self-inflicted wounds such as drunkenness, demons, and being unable to heal the dead or animals. Whitelighters are also only able to heal if they are supposed to. If they heal someone they are forbidden by the Elders to help, their wings can be clipped as punishment, like when Leo healed Piper when she had Oroya Fever.
The Elders told Leo not to heal her but he did and when the Elders found out, they clipped his wings temporarily and suspended him. While Leo has shown the ability to heal himself if his body sustains injuries that would be fatal if he was human- such as when he was stabbed with a butcher knife-, this ability does not extend to magically-induced injuries, and apparently takes a conscious effort on Leo's part as he cannot heal himself from being knocked unconscious but must recover on his own.
Paige Matthews, being only half whitelighter, did not have the power to heal for several years, until she admitted her love for her future husband Henry Mitchell during a bank robbery. Before she found her trigger, she had to channel her healing abilities through Leo.
Healing, in the comics.In the earlier seasons, a little lightbulb would be used for the healing light. The lightbulb would be attached to palm of the actor's hand and the wire (which would be hidden in the sleeve) was connected to a little power box in the back pockets of the actor's pants or in a jacket. For some shots, the light was added by computer. Paige's healing in season 8 was all done by computer, most noticeably, by the coloring and opacity of the light looking unnatural.
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