Hatha Yoga describes Shatkarmas (six processes) in details for Body purification and mind purification. Various asanas (Yoga Positions), six shatkarmas, mudras & bandhas (psychic knots or psycho-physiological energy release techniques) and Pranayama are described in old ancient sanskrit texts of Hatha Yoga (Hatha Yoga Pradipika and Gherandasamhita).
Yoga has considered internal purification of the human body in depth. The shuddhikriyas (Cleansing Process) have been planned with a view to have total purification of the body before various samskaras are made thereon for baking the body in the fire named Yoga so as to turn the body into a ripe vehicle. The organs where there can be a lot of impurities require these shuddhikriyas. The internal organs, which come into contact with the external matters regularly, need to be purified. The trachea regularly comes into contact with the external air, the food pipe comes into contact with the external food products, and the mind comes into contact with the thoughts of the external world; these and such other organs need to be purified internally. Hence the shuddhikriyas. Certain elements are cured with these kriyas. Ayurveda has described these shuddhikriyas by the name of Panchkarmas. However, these panchkarmas take help of certain medicines and herbs. In the shuddhikriyas stated in Yoga, the emphasis is on the natural method. Many shuddhikriyas have been described in the Yoga texts. We will consider some of them in this syllabus. Direct study of these shuddhikriyas is expected over here.
While studying shuddhikriyas, one should consider the important difference in other yogic processes and the shuddhikriyas. Other yogic processes invariably form part of the daily activity of the human life, but these shuddhikriyas are not to be practiced daily. In fact they are not meant as part of the daily routine. When it is necessary to purify the body, these kriyas may be practiced daily, but when the need is over, the practice is stopped. It cannot generally be stated over here, when the need arises. It depends on each and every individual hence, the processes will be taught over here, but they are not to be practiced daily, but according to the duration which each individual may need. The duration may be different for each shuddhikriya. The detailed description of each shuddhikriya is given but it is enough to remember that shuddhikriyas are not to be practised like asanas and pranayam in day-to-day life.