In Hinduism, an individual is considered to be composed of three bodies: the karana sharira, linga sharira (subtle body), and karya sharira (gross body). These three bodies are connected and a person functions best when the bodies are in harmony with one another.
The karana sharira is what continues on after the other bodies are gone, and is the “seed” for a new life in a new body. In some Hinduism schools of thought, the karana sharira is considered the atman, while opposing schools consider the atman separate from the causal body.
The three-body concept is an important core belief in Indian philosophy and in yoga. Yogis seek to balance the bodies through their practice. If a body is imbalanced or unconnected, it can cause negative effects such as disease and/or confusion.