Surya Bhedi and Chandra Bhedana Pranayama

The word "surya" means the sun and "bhedi" means one that can pierce. Thus the literal meaning of Surya Bhedi is to pierce or energize the right/Sun/heating nostril. Chandra means the moon and represents the cooling energy of the moon.
Surya Bhedi (also called Surya Bhedana) pranayama can stimulate and awaken energy both in the physical and the pranic bodies. In particular, it can activate and energize the Pingala Nadi, which is associated with the right nostril or the "sun" nadi and the sympathetic nervous system. Chandra Bhedi (or Bhedana) is just the opposite of Surya Bhedi and activates the Ida Nadi which is associated with cooling aspect and the parasympathetic nervous system.

Surya Bhedi Pranayama

• Sit erect in habituated posture with your waist and neck in one straight line. 
• On this pranayama, the inhaling is done by the right and the exhaling by the left nostril repeatedly. 
• Inhale as much as you can by the right nostril slowly and fill the breath in the neck, heart and stomach completely so as to feel that from head to toe the whole body is full of breath. 
• When you begin to feel uneasy, close the right nostril and exhale with the left one. 
• Note that while inhaling, there is a soft and continuous sound and while exhaling, there is similar flow. 
• Start with three pranayamas and increase by one or two in a day till you reach twenty-one or even thirty one according to your physical capacity. 
• This practice must be done in winter but those who are of wind and phlegm humour can do it even on summer on hills.

Benefits:

1. This Pranayama increases bile and destroys phlegm and wind.
2. It promotes digestion and purges the body of all impurities by causing perspiration.
3. The Gherand Samhita says, “ The Surya Bhedi Kumbhaka delays death and old age. It awakens Kundalini and increases digestion.”

Chandra Bhedana Pranayama

“Chandra” in “Moon” and Chandra Bhedana Pranayama is a cooling pranayama. The moon corresponds to the introspective, passive and artistic aspects of an individual’s personality..

• Keep the spinal cord erect and sit in habitual posture. 
• With the thumbs of the right hand, press the right nostril and inhale through the left nostril (Chandranadi)  while making sound. 
• Retain the breath contained in throat, lungs and stomach. 
• After as much retention as possible, exhale through right nostril slowly and repeat it for as many times as you like. 
• This pranayama is also known as left nostril breathing because while doing this pranayama, the breathing is done through the left nostril.

Benefits:

1. When the inhalation is done through the left nostril, your body gets cooled.
2. It reduces the bile and removes the excess heat of the body. You do not feel tired and belching is stopped.
3. The benefits of this pranayama are quite opposite to those of Suryabhedi.
4. Therefore, a person of the nature of bile should practice it in summer. If the left nostril due to cold or catarrh be closed, then lie on your right side and& make the left nostril work and then start practice. You will learn how to know whether the right or left nostril is working.