Nidana is a Sanskrit word that means "cause, motivation or occasion" depending on the context. The word is derived from ni (down, into) and da (to bind, dana). It appears in the Rigveda, such as hymn 10.114.2, and other Hindu scriptures, wherein it means "primary or first cause, linked cause"; in other contexts such as Rigveda 6.32.6, nidana refers to a rope or band that links, binds or fastens one thing to another, such as a horse to a cart.
Nidana doctrines of Buddhism are attributed to Shakyamuni Buddha. It has two specific meanings. The more common use refers to the Twelve nidanas or "a concatenation of cause and effect", which is the cycle of rebirth as described by Gautama upon which a re-becoming is thought by Buddhists to rest, which is also called the twelve links of 'dependent origination'.
The term is also less commonly used with reference to the jhanas or stages of Buddhist meditation. The Twelve nidanas of samsara describe the stages of successive rebirths, based upon ignorance, while the nidana of the jhanas, by contrast, arises from spiritual practice.
An important example of nidanas in Buddhism, is the Twelve Nidānas doctrine where each link is asserted as a primary causal relationship between the connected links. These links present the mechanistic basis of repeated birth, Samsara, and resultant Dukkha (suffering, pain, unsatisfactoriness) starting from avidyā (ignorance, misconceptions).
The term Nidana appears in numerous ancient and medieval Hindu texts wherein it means "first cause, primary cause, original or essential cause". This includes the Upanishads that include theosophical speculations, as well as medical texts such as Sushruta Samhita and Charaka Samhita where a large sub-book is titled Nidana-sthana, as well as in chapters of the Puranas, wherein these discuss cause of disease or various natural phenomena.