Ida and Pingala
The left nostril is associated with Ida Nadi — the lunar, cooling and feminine quality. It supports rest, intuition, creativity, reflection and meditation.
The right nostril is associated with Pingala Nadi — the solar, warming and masculine quality. It supports action, logic, physical work, digestion and outward engagement.
Neither is better than the other. Health lies in moving effortlessly between the two.