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.