Dhauti, basti, neti, trāṭaka, nauli, and kapālabhāti — these are known as the six karmas.

This verse enumerates the six purificatory acts (ṣaṭkarmas) of haṭha yoga. Each one has a specific purpose in the purification of the physical and energetic body.

Dhauti cleanses the upper digestive tract through various techniques, including the swallowing of a muslin cloth. Basti purifies the colon through yogic enema techniques. Neti cleanses the nasal passages using salt water or a cotton thread. Trāṭaka purifies the eyes and develops concentration through steady, unblinking gazing.

Nauli is the massage of the abdominal organs through the isolation and rotation of the rectus abdominis muscles. Kapālabhāti (literally “skull shining”) cleanses the respiratory passages and stimulates the brain through rapid, vigorous exhalations. Together, these six karmas prepare the body for the subtler practices of prāṇāyāma.