The Buddha said, "Mind is the main thing and it is the leader." The body is not our identity. Mind is our identity. It is who we are. So from the Buddha's perspective, working with the mind is the basis of health and healing. If our mind is loving and peaceful, we spontaneously will become stronger and wiser, even if our bodies have difficulties. The way to achieve this is through the practice of loving-kindness.
According to Tibetan medicine, a calm and joyful mind will help to balance the four elements - earth, water, fire, and air - that are the building blocks of our body, and make the circulation of our energy system function normally. And at the end of our life, when our mind leaves the body and begins to migrate, the healthy experiences we have generated through the practice of loving-kindness will assure us a peaceful and joyful rebirth. So if we honestly wish to take care of ourselves and serve this planet in a meaningful way - to heal ourselves and others - it is true loving-kindness that we must generate firmly in our own heart and mind.
Written by Tulku Thondup Rinpoche. Published in Shambhala Sun, March 2009 in an article entitled: Loving-Kindness is the Best Medicine.