The term Hath Yog has been commonly used to describe the practice of asan (postures). The syllable 'ha' denotes the pranic (vital) force governing the physical body and 'tha' denotes the chitta (mental) force thus making Hath Yog a catalyst to an awakening of the two energies that govern our lives. More correctly the techniques described in Hath Yog harmonise and purify the body systems and focus the mind in preparation for more advanced chakra and kundalini practices.

The Hath Yog system includes asan along with the six shatkarm (physical and mental detox techniques), mudra's and bandh's (psycho-physiological energy release techniques) and Pranayam (pranic awakening practices). Fine tuning of the human personality at increasingly subtle levels leads to higher states of awareness and meditation.

Hath Yog Pradipik is one of the most authentic text books on Hath Yog, written in 1200 AD by Swami Swatmaram, a great Yog Guru who formulated the principles of Hath Yog and systematically explained various techniques, its effects on body, mind and states of consciousness. This is a comprehensive text on asans, Pranayam, Cleansing techniques, Mudra's (Mental attitude or gestures), Bandh's (Energy locks), Nad (Sound) Meditation and many more guidelines for following the path of Yog.

Swami Swatmaram was the follower of Nath Tradition, (followers of Adi Nath or Lord Shiv), taught by great Gurus like Gorakshanath and then Matsyendranath. This is the tradition of sages who live in caves or Himalay's and renounce material life adopting sanyas.

Let us see the meaning of word Hath, it is made up of Ha + Tha. "Ha" means Pingala Nadi (sun principle) or right nostril and "tha" means Ida nadi, (moon principle) or left nostril. Nadi means psychic passage of energy which can be compared with nerves in physical body. Hath means balance of Ida and Pingala Nadis, or balancing of mental energy of Ida and Vital / physical energy of Pingala Nadi. Ida Nadi can be compared with Parasympathetic Nervous system and Pingala nadi can be compared with Sympathetic Nervous System. So Hath Yog practices results in balancing the entire nervous system resulting in balance of Body and Mind, physical energy and mental energy. The basic purpose of Hath Yog is to purify the Ida and Pingala Nadis and then uniting these 2 forces with the third Psychic Nadi Sushumna, which carries Kundalini at Ajna Chakra (eyebrow center).

Hath Yog Pradipik starts with the Satkarm or cleansing processes, these processes are to remove the blockages in Nadis (psychic / pranic energy channels). A particular disorder or disease is due to blockage in pranic channel supplying vital / bio energy to the particular organ related to disorder. Cleansing techniques removes this energy blocks and the pranic energy starts flowing without hurdles, thus balancing the entire body and mind. The purification is the first in Hath Yog, once the body is free of disease, the next step is recommended and that is asans.

Hath Yog Pradipik outlines the purpose of asan's, which says that "One can achieve Sound Health, Stability, Lightness of Body and Mind with asan". asan result in disciplining the Body and Mind.

After the asans comes Pranayam, it is made up of Prana + Ayam, which means the control and extension of the Pran or vital energy or bio energy. Pranayam, if practiced correctly can cure all types of physical and mental disorders, also increase in pranic energy can increase functioning of brain and may result in Siddhi's or perfections or extra sensory perceptions, Pranayam is used to control the mental energy and mind. But if pranayam is not done properly, it invites all the diseases. So it must be done under the guidance of Guru.

Pranayam is considered as a fast way to awaken the kundalini. But if one is not prepared to take on this high level energy awakening then this may have negative effects on mind and body. So Pranayam is always practiced under the guidance of Guru.

Bandh's are necessary for practice of Pranayam, Bandh means energy lock. There are main 3 types of locks, first is Jalandhar Bandh or Chin lock, second is Moolabandh or anus lock and third is Uddiyan Bandh or abdominal lock. These locks are essential while doing the Kumbhak that is retaining the air inside or outside of the lungs. If Kumbhak or retention is done without Bandhas, it may have a very negative effect.on digestive system, excreatory system, nervous system, brain, etc.

Hath Yog also describes Mudra's or gestures or Mental attitude, which induce the state of Pratyahar (Sense withdrawal) and results in spontaneous state of meditation. Several mudras are mentioned in the Hath Yog which include, Vajroli Mudra, Sahajoli Mudra, Khechari Mudra, Shambhavi Mudra, Viprit Karani, etc.