Pranayma (The science of breathing)

Pranayama is the fourth constituent of yoga. It is very helpful in making mental and spiritual progress. It is equally important for physical improvement and maintaining health. Breathing is the most essential means of sustaining human life. We can live for some time without food, water, but without inhaling and exhaling air, it is not possible to liver longer than a few minutes.
The ordinary way of breathing is to inhale and exhale in a regular manner, that is, inhaling, retaining and exhaling in a regulated and natural continuity. Such natural breathing, when controlled and prolonged successfully, is called pranayama or the science of breathing.

Breathing properly practiced, cures all diseases, but improperly done, it cause all ailments. By irregular breathing many troubles like hiccups, cough, asthma, headache, earache and eye diseases etc. are caused. The aspirant should put himself under the tuition of an instructor who after duly considering the locality, time, physical capacity and the nature of health of the aspirant can give correct directions.

It practiced along with the yogic postures, the effects or benefits purification of body and minds has inevitably to practice this part of yoga.
The yoga sutra says that by the practice of yoga impurities disappear and knowledge begins to shine and culminates in self-realization.

Precautions:
The breathing exercises should be done at leas three or four hours after meals and the food should consist mostly of milk, ghee, rice, porridge, bread, vegetables, khichari, fruits, and dried fruits which are easily digestible and absorbable objects may be preferred.
Patients having high temperature and pregnant woman should not in any case take breathing exercises. This is equally applicable also to those who are hungry or have their stomachs full.
The breathing exercises should not be taken after merely reading books on the subject or even observing others at practice of these. In the earlier stages the exercises should be done under the guidance of experienced instructors.
For acquiring the power of meditation, breathing exercises should be done, while keeping the spinal cord, waist, chest and neck in one straight line only. Then the exercises will give the desired results.
For gaining the fullest benefit from the breathing exercises, one should control one's diet, behavior, activities, actions, sleeping and working hours. These rules must be strictly observed.
The postures and the breathing exercises should not be taken in an atmosphere of smoke, dust foul smell or dampness. If this rule is not adhered to, more harm is possible than good.

Types of Pranayama:
1. Ujjayi Pranayama
2. Surya Pranayama
3. Sitkari Pranayama
4. Shitali Pranayama
5. Bhastrika Pranayama
6. Bhramari Pranayama
7. Murchha Pranayama
8. Plavani Pranayama

Benefits:
The yoga sutra says that scientific breathing (Pranayma) dispels the curtain of darkness concealing knowledge. It enables the mind.