Diseases, death, enemies, and even relatives cause difficulty through the mind, not by their own nature.

The list of agents of kaṣṭa is exhaustive: the organic (vyādhi), the inevitable (mṛtyu), hostile external forces (śatravaḥ), and beloved external beings (svajanāḥ). They all share the same structure: kaṣṭa does not reside in the object itself, but in the mental relationship one has with it. The death of a stranger is a statistic; the death of a son is a tragedy. A declared enemy is less dangerous than a friend who betrays you. The vastu-svabhāva—the inherent nature of the thing—is neutral; what turns it into kaṣṭa is cetana, the act of consciousness that interprets it. This is not solipsism: the event occurs, the pain is real, but the additional suffering—the “why me,” the “I didn’t deserve this,” the “all is lost”—is mentally generated. Yoga Sūtra II.5 defines avidyā as taking the impure for pure, the painful for pleasurable. Here it is inverted: taking what is neutrally painful as personally devastating is the root of expanded kaṣṭa.