There are the two nadis, nerve-currents one on either side of the spinal cord. Surya nadi is the right and Chandra nadi is the left nostril. They are also called Ida and Pingala, respectively. The Sun flows through the Pingala (right) and the Moon through the Ida (left).
Quite naturally, Pingala is heating while Ida is cooling. In Suryabhedana one always uses the right nostril for inhalation. Sit in sukhasana or any comfortable posture.
Keep the head, neck and back erect. Inhale through the right nostril, then exhale through the left nostril. Repeat as often as required.
Suryabhedana purifies the blood and destroys intestinal worms. Besides, it eradicates indispositions caused by Vata and, particularly helps cure rheumatism, helps increase gastric juices, enhance digestion and concentration at work. It also fortifies the nervous system and clears the sinuses. People with Vata and Kapha prakriti are usually advised this pranayama.