This is an excerpt from the book "Tibetan Yogas of Dream and Sleep" by Tenzin Wangyal Rinpoche that we liked very much because it is a very clear and practical explanation of the Nine Purification Breaths. Hopefully, you will find it useful too: Perhaps you have noticed how much tension is carried in the body and how the tension affects breathing. When someone with whom we are having difficulties walks into the room, the body tightens and the breath becomes shorter and sharper. When we are frightened, the breath comes quick and shallow. In sadness, the breathing is often deep and punctuated by sighs. And if someone we genuinely like and care for enters the room, the body relaxes and the breath opens and eases.