Definition - What does Ida mean?
Ida is one of the three basic nadis (energy channels) found in the astral body. According to Tantric texts, the human body has 72,000 nadis. All of these nadis originate from three fundamental nadis -- namely ida (left), pingala (right), and sushumna (center).
Like chakras, nadis are invisible and their proper function is essential to staying healthy. Regular practice of yoga helps to achieve balance between the ida and pingala nadis, which ensures both physical and psychological health.
Yogapedia explains Ida
As the leftmost channel, ida emanates from the left of the muladhara (root chakra) and passes through all the chakras in curves, ending to the left of ajna (third eye chakra). Its opposite, pingala, is the right channel, which starts from the right of the muladhara and ends to the right of ajna. Ida is negative and pingala is positive.
Ida is the lunar nadi and, hence, is considered cool and dominantly feminine. Ida purifies both the body and the mind, and is sometimes referred to as river Ganges, which is considered sacred. Ida's energy is white and it is responsible for all mental processes as it regulates the function of the parasympathetic nervous system. Ida influences the right side of the brain. When ida is too dominant in the energetic body, it results in fatigue, depression and a lack of mental clarity.
Hatha yoga aims to balance ida and pingala in order to awaken kundalini, thereby leading the practitioner to a state of higher consciousness. The ha in hatha represents solar force, while the tha represents lunar qualities. Hatha yoga practice helps to balance the solar and lunar forces and clears the path for kundalini flow, which elevates the practitioner's consciousness to a higher plane and makes them feel at one with the universe.