Yog Vasishth describes a discussion between Shree Ram and the Sage Vasishth. When Lord Ram saw disease afflicting the people of His kingdom, He was moved by compassion, and asked His teacher about the cause of disease. Sage Vasishth explained that firstly the mind becomes disturbed due to negative thoughts, such as thoughts of anxiety, hatred, tension, regret, remorse, lamentation, etc.
This causes a disturbance at the level of the prāṇs, or the “life giving forces”. This manifests in the next stage, i.e. in the physical body, as disease. Hence, if we wish to cure disease from the root, we must address the mind.