This question has puzzled many energy practitioners for centuries, and no one really knows how to answer how Reiki works. What is known is that Reiki transfers positive energy into the body via a channel or the Reiki practitioner and it balances and heals the existing energy within the recipient’s body. The Reiki recipient should notice a physical, mental, and spiritual improvement after a treatment. During the session, it is possible to feel heat, tingling, or a swirling sensation or they may feel nothing all, but whether the recipient feels anything, Reiki energy is still working. It is important to note that the Reiki practitioner is not working with their own energy, and they do not experience a drop in their own energy level during a session. When they give Reiki to another, they also get Reiki in return; it truly is the gift that keeps on giving.
Sometimes when a Reiki practitioner is channeling Reiki energy to a client, they get intuitive messages during the session. As a practitioner develops their Reiki skills and if they are already strong intuitively or empathetic, channeling may come naturally. Reiki enhances our God-given abilities and helps us tune into the world around us, so these spiritual gifts heighten as the practitioner grows.
My personal experience has been that the more I use Reiki on myself (self-Reiki) and others, the stronger my intuitive gifts grow. I started down this path as an empath that sometimes-experienced clairaudience (clear hearing). What I learned was that I was empath, but I was extremely clairsentient (clear feeling) as well; I had just repressed that gift. Reiki brought that gift back to the surface. When I am working with a client, I can feel their physical symptoms and can receive messages about their health.
Whatever gifts the practitioner or recipient has will be heightened with Reiki energy.