Mindstream is the Buddhist concept of continuity of consciousness across lifetimes. Different schools of Buddhist thought define this concept differently, but it is generally defined as a form of consciousness that exists both before and after a single physical lifetime. The consciousness that exists within a person’s mindstream exists independently of the personality and the conscious self.
Buddhism makes a distinction between the idea of individual awareness and a continuum of awareness that transcends an individual’s lifetime. The concept of individual awareness can be thought of as a personality or even as a soul to those who believe that the personality survives death. In many strains of Buddhist philosophy, the individual awareness is contained within the physical mind of a person and only exists for the duration of that person’s lifetime. Though many Buddhists believe that the personality dies along with the physical body, most also believe that a part of that person, the mindstream, continues to exist after physical death.
According to Buddhist teachings, the mindstream exists independently of a person’s body. It is an awareness that joins with a person during fetal development and separates from that person at the time of death. The mindstream is not a self but is something that transcends the self and continues to exist once the self does not. This consciousness exists in and flows through all phases of samsara, which is the cycle of birth, life, death, and rebirth.
Karma is also said to arise out of a person’s mindstream. Though karma itself is not inherently good or bad, the actions and thoughts that a person engages in become a part of that person’s consciousness and can lead to positive and negative experiences. Sickness, according to Buddhist philosophy, can be cured and prevented by engaging in positive actions in the present and by clearing the mindstream of negative karma from the past. Being mindful of thoughts and actions and avoiding those that bring harm to others is one way to eliminate negative karma.
Buddhist teaching does not recommend forgoing medical treatment and relying solely on clearing out negative karma from the mindstream as a treatment for disease. The body can be healed using medical treatments, though if negative karma is still in the mindstream, sickness will return either in this or in another lifetime. The only way to achieve lasting healing is to correct the issue at the source, in the mindstream of the person.